GF signet 2551 User manual

3-2551.090-1 Rev. M 04/15
Signet 2551 Display Magmeter
English
The 2551 Magmeter measures the flow rate in a full pipe by monitoring the voltage
produced when the (conductive) fluid moves through a magnetic field. Output
options include a traditional frequency signal, a serial data (Digital (S3L)) output,
and a 4 to 20 mA output.
The 2551 Magmeter is available in three sizes that will accommodate pipes from
½ inch through 36 inch diameters.
Select from three different material combinations to match the Magmeter to the
application requirements.
Operating Instructions
Description
Table of Contents
Warranty Information .............................................................................. 2
Product Registration............................................................................... 2
Safety Information .................................................................................. 2
Chemical Compatibility........................................................................... 2
Dimensions............................................................................................. 2
Specifications ......................................................................................... 3
Installation .............................................................................................. 4
Pipe Fittings ........................................................................................ 4
Selecting a Location............................................................................ 4
Overview Magmeter Display................................................................... 5
Wiring ..................................................................................................... 5
Mirror Relay 1 Output.......................................................................... 5
Frequency Output ............................................................................... 5
4 to 20 mA Output............................................................................... 6
Wiring to other Manufacturer's Instruments ........................................ 6
Wiring to Signet Flow Instruments ...................................................... 6
Wiring Relays...................................................................................... 7
Application Notes: Relay Wiring...................................................... 7
Navigating the Menus............................................................................. 8
Keypad Functions ............................................................................... 8
Security Code ..................................................................................... 8
View Menu.............................................................................................. 9
Resetting the Resettable Totalizer ...................................................... 9
Setup Menu .......................................................................................... 10
Averaging and Sensitivity...................................................................11
Bi-Directional Flow............................................................................ 12
Calibration Data: K-Factors.......................................................... 12-13
Calibration Menu............................................................................... 14
Volume Method of Calibration........................................................... 14
Rate Method of Calibration ............................................................... 14
Relay Menus......................................................................................... 15
Pulse Relay Mode............................................................................. 15
Total Relay Mode .............................................................................. 15
High, Low, or Window Relay Modes ................................................. 16
Test Menu ............................................................................................. 17
Options Menu ....................................................................................... 17
Output Modes ................................................................................... 17
Grounding............................................................................................. 18
Maintenance......................................................................................... 18
Troubleshooting.................................................................................... 19
Ordering Information............................................................................. 20
*3-2551.090-1*
• English
• Deutsch
• Français
• Español
• Italiano
• Português

2Signet 2551 Display Magmeter
1. Depressurize and vent system prior to installation or removal.
2. Confirm chemical compatibility before use.
3. Do not exceed maximum temperature / pressure
specifications.
4. Wear safety goggles or faceshield during installation/service.
5. Do not alter product construction.
Failure to follow these instructions may result
in the sensor being ejected from the pipe!
If leaking is observed from the retaining cap, it
indicates defective or worn o-rings on the sensor.
Do not attempt to correct by further tightening.
Caution / Warning / Danger
Indicates a potential hazard. Failure to follow all warnings
may lead to equipment damage, injury, or death
Electrostatic Discharge (ESD) / Electrocution Danger
Alerts user to risk of potential damage to product by
ESD, and/or risk of potential of injury or death via
electrocution.
Personal Protective Equipment (PPE)
Always utilize the most appropriate PPE during
installation and service of Signet products.
Pressurized System Warning
Sensor may be under pressure, take caution to vent
system prior to installation or removal. Failure to do so
may result in equipment damage and/or serious injury.
Hand Tighten Only
Overtightening may permanently damage product
threads and lead to failure of the retaining nut.
Do Not Use Tools
Use of tool(s) may damage product beyond repair and
potentially void product warranty.
Note / Technical Notes
Highlights additional information or detailed procedure.
Refer to your local Georg Fischer Sales office for the most
current warranty statement.
All warranty and non-warranty repairs being returned must
include a fully completed Service Form and goods must be
returned to your local GF Sales office or distributor.
Product returned without a Service Form may not be
warranty replaced or repaired.
Signet products with limited shelf-life (e.g. pH, ORP, chlorine
electrodes, calibration solutions; e.g. pH buffers, turbidity
standards or other solutions) are warranted out of box but not
warranted against any damage, due to process or application
failures (e.g. high temperature,
chemical poisoning, dry-out) or
mishandling (e.g. broken glass, damaged membrane, freezing
and/or extreme temperatures).
Thank you for purchasing the Signet line of Georg Fischer
measurement products.
If you would like to register your product(s), you can now
register online in one of the following ways:
• Visit our website www.gfsignet.com.
Under Service and Support click on
Product Registration Form
• If this is a pdf manual (digital copy), click here
Chemical Compatibility
116.8 mm
(4.6 in.)
-X0
-X1
-X2
95.3 mm
(3.75 in.)
Dimensions
Warranty Information
Product Registration
Safety Information
The retaining nuts of Magmeters are not designed for
prolonged contact with aggressive substances. Strong acids,
caustic substances and solvents or their vapor may lead to
failure of the retaining nut, ejection of the sensor and loss of
the process fluid with possibly serious consequences, such as
damage to equipment and serious personal injury. Retaining
nuts that may have been in contact with such substances e.g.
due to leakage or spilling, must be replaced.
Pipe Range Insertion Depth
½ in. to 4 in. -X0 = 58 mm (2.3 in.)
5 in. to 8 in. -X1 = 91 mm (3.6 in.)
10 in. to 36 in. -X2 = 167 mm (6.6 in.)
X = Sensor Body Material (P, T, or V)
DO NOT USE thread sealant
or lubricants on the fitting threads!
Do not use any tools to
tighten the yellow retaining cap.
DO NOT USE thread sealant or
lubricants on retaining cap!
Lubricate O-rings with a
non-petroleum based, viscous
lubricant (grease) compatible
with the system.

3
Signet 2551 Display Magmeter
Power Requirements
4 to 20 mA .....................21.6 to 26.4 VDC, 22.1 mA max.
400 mV p-p maximum ripple voltage
Frequency......................5 to 26.4 VDC, 15 mA max.
Digital.............................5 to 6.5 VDC, 15 mA max.
Auxiliary.........................9 to 24 VDC, 0.4A max
(only required for units with relays)
Reverse polarity and short circuit protected
Current output (4 to 20 mA)
Max Loop Resistance....300 
Loop Accuracy...............32 A max. error (25 °C @ 24 VDC)
Temp. drift......................± 1 A per °C max.
Power supply rejection ...± 1 A per V
Isolation: .......................Low voltage < 48 VAC/DC from
electrodes and aux power
Maximum cable .............300 m (1000 ft)
Error condition ...............22.1 mA
Frequency output
Output modes................Freq, Freq÷10, or Mirror Relay 1
Max. Pullup Voltage.......30 VDC
Max. Current Sink..........50 mA, current limited
Maximum cable .............300 m (1000 ft)
Reverse Polarity Protected to -40 V
Digital (S3L) Output
Serial ASCII, TTL level 9600 bps
Compatible with Signet 8900 and 9900
Maximum cable ......Application dependent (See 8900 manual)
Relay Specifications
Relay 1 and 2 Type........Mechanical SPDT
Rating ............................5 A @ 30 VDC max.,
5 A @ 250 VAC max.
Relay 3 Type..................Solid State
Rating ............................50 mA @ 30 VDC, 50 mA @ 42 VAC
Hysteresis......................Adjustable, plus timer delay
Trigger Delay .................Adjustable (0 to 9999.9 sec.)
Relay Modes..................Off, Low, High, Window, and
Proportional Pulse
Relay Source.................Flow Rate, Resettable Totalizer
Error Condition ..............Selectable; Fail Open or Fail Closed
Display
Characters.....................2 x 16
Contrast.........................User-set in four levels
Backlighting ...................Requires external 9-24 VDC,
0.4 mA max. (only on relay versions)
Environmental Requirements
Enclosure ......................NEMA 4X / IP65 (with cap installed)
Case ..............................PBT
Display window..............Polyamide
Storage Temperature.....-20 °C to 70 °C (-4 °F to 158 °F)
Relative Humidity...........0 to 95% (non-condensing)
Operating Temperature:
Ambient......................-10 °C to 70 °C (14 °F to 158 °F)
Media .........................0 °C to 85 °C (32 °F to 185 °F)
Operating pressure:
Maximum ...................10.3 bar @ 25 °C (150 psi @ 77 °F)
1.4 bar @ 85 °C (20 psi @ 185 °F)
Specifications
General
Pipe size range..............DN15 to DN900 (½ in. to 36 in.)
Flow Range ...................Minimum: 0.05 ms (0.15 ft/s)
(Bi-directional) ...............Maximum: 10 ms (33 ft/s)
Linearity.........................±1% of reading +0.01 ms (0.033 ft/s)
Repeatability..................±0.5% of reading @ 25 °C (77 °F)
Minimum Conductivity ...20 S/cm
Wetted Materials
Sensor body and Electrodes and Grounding ring:
-P0, -P1, -P2 ..............Polypropylene and 316L SS
-T0, -T1, -T2...............PVDF and Titanium
-V0, -V1,-V2 ...............PVDF and Hastelloy-C
O-rings .......................FPM (standard) EPDM, FFPM
(optional)
The user is responsible for determining
the chemical suitability of these materials
for a specific application.
Standards and Approvals
• CE
• UL/CUL (for display versions with relays)
• NSF (3-2551-P versions only)
• RoHS compliant
China RoHS (visit gfsignet.com for details)
• Manufactured under ISO 9001 for Quality, ISO 14001
for Environmental Management and OHSAS 18001 for
Occupational Health and Safety.
Declaration of Conformity according to FCC Part 15
This device complies with Part 15 of the FCC rules.
Operation is subject to the following two conditions:
(1) This device may not cause harmful interference, and,
(2) This device must accept any interference received,
including interference that may cause undesired operation.
10
20
30
40
50
60
70
80
90
100
110
120
130
140
150
160
170
180
.7
1.4
2.1
2.8
3.4
4.1
4.8
5.5
6.2
6.9
7.6
8.3
9.0
9.7
10.3
11.0
11.7
12.4
(bar)(psi)
0
-20 020 40 60 80 100 120
°F
°C
-4 32 68 104 140 176 212 248

4Signet 2551 Display Magmeter
• The 2551 requires a full pipe and a fully developed turbulent flow profile for
accurate measurement.
• If the piping system harbors air pockets or bubbles, take steps to locate the
sensor so the air pockets will not contact the electrodes.
• In vertical installations, assemble the 2551 so the conduit ports are facing
downward. This prevents condensation inside the conduit from being directed
into the 2551 electronics housing.
• Chemical injection systems can temporarily alter the fluid conductivity and
cause anomalies in the magmeter measurement.
To avoid this problem, install the magmeter UPSTREAM of the injection point.
Reducer
15 x I.D. 5 x I.D. 20 x I.D. 5 x I.D.
90° Elbow
25 x I.D. 5 x I.D.
2 x 90° Elbow
40 x I.D. 5 x I.D.
2 x 90° Elbow
3 dimensions
50 x I.D. 5 x I.D.
Pump/Valve
Vertical flow is OK if the pipe remains full at all times.
+GF+
OK
+GF+
OK
+GF+
OK
Georg Fischer offers a wide selection of installation fittings that control the position of the Magmeter electrodes in relation to the
dimensions of the pipe. You will find a complete list of order numbers for installation fittings in the Calibration Tables on pages 12-13.
Select a location with sufficient distance of straight pipe immediately upstream of the sensor.
Locating the sensor in a trap or where
the flow is upward helps to protect the
sensor from exposure to air bubbles
when the system is in operation.
These configurations are not recommended
because it is difficult to keep the pipe full.
Type Description
• 2 to 4 inch, cut 1-7/16 inch hole in pipe
• Over 4 inch, cut 2-1/8 inch hole in pipe
• Special order 14 in. to 36 in.
• 0.5 to 2 inch versions
• MPVC or CPVC
• 2 to 4 inch, cut 1-7/16 inch hole in pipe
• 6 to 8 inch, cut 2-1/8 inch hole in pipe
• Available in 10 and 12 inch sizes only
• Cut 2-1/2 inch hole in pipe
• Weld in place using solvent cement
Iron, Carbon Steel,
316 SS
Threaded tees
Carbon steel &
stainless steel
Weld-on
Weldolets
• 2 to 4 inch, cut 1-7/16 inch hole in pipe
• Over 4 inch, cut 2-1/8 inch hole in pipe
• For pipes from DN 15 to 50 mm
• PP or PVDF
Type Description
Plastic
tees
Union Fittings and
Wafers
PVC
Clamp-on
Saddles
Iron
Strap-on
saddles
PVC
Glue-on
Saddles
• 1.5 in. to 2 in. PVDF insert
Fiberglass
tees
FPT
• 0.5 to 2 in. versions
• Mounts on threaded pipe ends
In a gravity-flow system, the tank must be designed
so the level does not drop below the outlet.
This causes the pipe to draw air in from the tank.
If air bubbles pass across the Magmeter electrodes,
the output will become erratic.
Pipe Fittings
Selecting a Location
+GF+
+GF+
ENTER
9900
2551
9900 2551
ENTER
Injection Point
Injection Point

5
Signet 2551 Display Magmeter
2551 Display Magmeters use a dual-sided electronics
module and dual conduit ports. Unused ports must be
sealed to protect the electronics from water damage.
1. The lower set of conduit ports provide access to the
wiring terminals for:
• Loop Power
• Flow Output Signal (current loop, Digital (S3L),
frequency or Mirror Relay 1 output).
2. The upper set of conduit ports provide access to the
wiring terminals for:
• Relay output wiring
• Auxiliary power for relay coils and display backlight
3. The sensor is marked with a directional arrow to indicate
the direction identified as forward flow.
• An adhesive decal is also provided that can be affixed
to the pipe to indicate the direction of forward flow.
• Flow in the opposite direction from the arrow will be
identified as reverse flow on the display by a "-" symbol.
4. The terminals in the magmeter are designed to
accomodate 16 to 22 AWG conductors.
5. The display includes two LEDs that light when
Relay 1 or Relay 2 are activated.
• All three relays can be monitored by scrolling to the
Relay Status display located in the View menu.
• If the Language option has not been made, new
magmeters will always open with the Select Language
display.
Language
English >
6. The part number, serial number and output type are
identified on the electronics module.
Signet Magmeter
RELAY 1 RELAY 2
ENTER
420 GPM
123456.78 >
3.
Relay 1
Relay 2
NO1
NO2
NO3
NC1
NC2
NC3
C1
C2
C3
V+
V-
Relay 3
Aux Pwr
4.
5.
4-20/freq out
s/n 60504201234
60504201234
p/n 3-2551-11
3-2551-11 6.
4.
1
2
3
4
4 to 20 mA output
Digital (S3L) output
Frequency output
Mirror relay 1 output
1.
Relay output
Aux power
2.
Overview of Magmeter Display
2551 Magmeter
4.5-26.4
VDC
Relay 1
Relay 2
NO1
NO2
NO3
NC1
NC2
NC3
C1
C2
C3
Relay 3
V+
V-
+ VDC
- VDC
Aux Pwr
3
Frequency Out
Frequency ÷ 10 Out
(5 to 26.4 VDC)
**********************
Digital (S L) Out
(4.5 to 6.5 VDC)
1
2
3
4
Auxiliary Power for:
Display backlighting
Relay Coils
Ground
Signal
3-2551-21 and 3-2551-41 Magmeters may be programmed
in the OPTIONS menu to provide an open collector
FREQUENCY output.
• The maximum frequency output is 1000 Hz
(at 10 meters per second)
• If the Frequency ÷ 10 output is selected, the maximum
frequency is 100 Hz (at 10 meters per second).
• AUX PWR must be connected to power the display
backlighting and to power the relay coils if included.
Wiring to Frequency Output
1
2
3
4
5-24 VDC
Ground
Not used
Open Collector Out
2551 Magmeter
The 3-2551-21 and 3-2551-41 Magmeter can be configured
in the OPTIONS menu to provide an Open Collector output
in lieu of the sensor signal provided by Frequency or Digital
(S3L) output selections. The Open Collector output can be
programmed via the Relay 1 menu.
Wiring to Mirror Relay 1 Output

6Signet 2551 Display Magmeter
The 3-2551-21 and 3-2551-41 Magmeter can be configured in the
OPTIONS menu to provide a Frequency or Digital (S3L) output.
Frequency and Digital (S3L) output can be used by Signet 8900
Multi-Parameter Controller and 9900 Transmitter.
2551 Frequency Out to 8900 Controller
3-8900.621C
I/O Module 3-8900.401-X
1
2
3
4
5
6
7
8
9
10
11
+5VDC (Black)
Freq. Input (Red)
GND (Shield)
+5VDC (Black)
Freq. Input 2 (Red)
S L (Red)
GND (White/Shield)
+5VDC (Black)
S L (Red)
GND (White/Shield)
3
3
Frequency
Input
1
Frequency
Input 2
OR
S3L
Input
2
S3L
Input
1
1
2
3
4
Ground
+5 VDC
Not used
Data
2551 Magmeter
2551 Digital (S3L) Out to 8900 Controller
3-8900.621C
I/O Module 3-8900.401-X 1
2
3
4
5
6
7
8
9
10
11
+5VDC (Black)
Freq. Input (Red)
GND (Shield)
+5VDC (Black)
Freq. Input 2 (Red)
S L (Red)
GND (White/Shield)
+5VDC (Black)
S L (Red)
GND (White/Shield)
3
3
Frequency
Input
1
Frequency
Input 2
OR
S3L
Input
2
S3L
Input
1
1
2
3
4
Ground
+5 VDC
Not used
Data
2551 Magmeter
Wiring to Signet Flow Instruments
The 3-2551-22 and 3-2551-42 Magmeters provide a passive
4 to 20 mA loop output.
• External loop power (24 VDC) is required.
• Factory standard calibration is 4 to 20 mA = 0 to 5 m/s.
• The 4 to 20 mA output can be spanned to any range,
from -10 m/s to +10 m/s.
• AUX PWR must be connected to power the display
backlighting and to power to the relay coils if included.
2551 Magmeter
Relay 1
Relay 2
NO1
NO2
NO3
NC1
NC2
NC3
C1
C2
C3
Relay 3
V+
21.6 to 26.4 VDC
V-
+ VDC
- VDC
Aux Pwr
4-20 mA Loop Output
1
2
3
4
Auxiliary Power for:
Display backlighting
Relay Coils
420
Wiring to 4 to 20 mA Output
When using the 2551 in a system with other manufacturer's
equipment, a 10 Kpull-up resistor (not supplied) may be
required to power the open collector output.
1
2
3
4
Frequency Out
2551 Magmeter
24 VDC
NO3
NC3
C3
Relay 3
V+
V-
5-24 VDC
Ground
Ground
Aux Pwr
Sensr Gnd
(SHIELD)
Sensr IN
(RED)
Non-Signet
Flow Instrument
Ground
Frequency Input
5-24 VDC Out
Auxiliary Power for:
Display backlighting
Relay Coils
10 KΩ
Pull-up Resistor
Wiring to other manufacturer's Instruments
2551 Frequency or Digital (S3L) Out to 9900 Transmitter
1
2
3
4
DATA
GND
V+
SHLD
2551 Magmeter
9900 Transmitter
+5 VDC
Ground
Not used
Frequency or (S3L)

7
Signet 2551 Display Magmeter
Relay 3 is a solid state relay. It can be applied exactly the same as a
dry contact relay, but the current rating is 0.2 A (200 mA) maximum.
Relay 3 is best suited to pulse applications and low voltage loads.
Relays 1 and 2 are dry contact relays rated for 5 A maximum current.
They are best suited for switching high voltage loads, such as AC
powered pumps and valves.
When used to switch inductive loads, the dry contact relays may be
damaged by arcing. Signet recommends the installation of a filter
device to prevent such damage.
3-8050.396 159 000 617 RC Filter kit (for relay use)
Relay 3 Type: Solid State
Rating: 50 mA @ 30 VDC, 50 mA @ 42 VAC
Relay 1, Relay 2 Type: Mechanical SPDT
Rating: 5A @ 30 VDC max., 5 A @ 250 VAC max
Solid State Relay 3:
50 mA max @ 30 VDC
50 mA max @ 42 VAC
NO1
NO2
NO3
NC1
NC2
NC3
C1
C2
C3
V+
V-
Auxiliary Power
9 to 24 VDC
0.4 A Maximum
Mechanical Relays:
5A @ 250 VAC
5A @ 30 VDC
Relay 1Relay 2Relay 3
Aux Pwr
Auxiliary power must be connected to operate the relays and to
power the display backlighting. Auxiliary power is fully isolated.
The Loop Power supply may be used for Aux power if the
power source provides a sufficient current rating.
Relay Terminal Legend:
NO: Normally Open
NC: Normally Closed
C: Common
Application Notes: Relay Wiring
• Inductive relay loads may generate transient voltage spikes well in excess of the relay contact ratings. This will cause arcing across
the contacts and consequently rapid relay wear. Signet recommends an RC-style filter (“snubber”), installed as illustrated here.
•The filter kit (3-8050.396) is available as an accessory item. See ordering information on back cover.
• Signet product warranty does not cover damage to relays due to contact burnout.
3-8050.396
NO1
NO2
NO3
NC1
NC2
NC3
C1
C2
C3
V+
V-
120-240 VAC
AC-powered:
Pumps
Alarm lamps
Audio alarms
Mixers
Definition:
An inductive load is an electrical device generally
made of wire that is coiled to create a magnetic field
to produce mechanical work when energized.
Examples of inductive loads include motors,
solenoids, and relays.
High voltage transients from these types of loads can
cause arcing across mechanical switching contacts
or can cause damage to solid-state contacts.
Wiring Relays

8Signet 2551 Display Magmeter
Security CodeKeypad Functions
Navigating the Menus
The 2551 has a security code that can be programmed to any
four-digit numerical value.
• The factory setting is 0-0-0-0.
• To program the security code go to the Options menu.
• The security code will be required to edit any of the items in
the menus. It is required only once for each editing session.
• Record the custom security code here or in a safe location.
• If the security code is lost, contact your Signet service
center for instructions.
Normal Operation Display
The normal operating display shows the Flow Rate on the top line and the Resettable
Totalizer on the bottom line.
• All menu instructions in this manual assume that the instrument is showing this display.
Calibration Menu
This menu provides two different methods for adjusting the calibration. See page 14 for details
related to this menu.
Setup Menu
This menu contains all of the settings and information that the magmeter requires to operate,
including the K-Factor, the totalizer settings, low flow cutoff, and several display characteristics.
See page 10 for details related to this menu.
2551 Menu Directory
The 2551 Magmeter uses seven main menus to provide access to the calibration and
programming features. Each menu serves a specific function.
Starting from the normal operating display, there are two ways to access the menus:
1. Press the key to scroll to the Enter Menu display, then press the key.
2. Press the ENTER key and hold it for about three seconds.
Enter Code
0000
3s
ENTER
Or
Signet Magmeter
RELAY 1 RELAY 2
ENTER
1234.56 GPM
876543.21 >
Enter Menu
>
Enter Menu
Setup >
Enter Menu
Calibration >
Enter Menu
Relay 1 >
Enter Menu
Relay 2 >
Enter Menu
Relay 3 >
Enter Menu
Test >
Enter Menu
Options >
Scrolls UP through any menu.
If the display shows any flashing character or selection,
scrolls UP to the previous value or selection.
Scrolls DOWN through any menu.
If the display shows any flashing character or selection,
scrolls DOWN to the next value or selection.
Press the and keys together to abandon any
unsaved edits and return to the previous display.
Opens the menu currently being displayed.
In Edit modes, advances the flashing character.
In menus with only two options (Yes or No, On or Off)
toggles between selections.
ENTER
Saves a new selection in any menu.
From Normal Operation display, jumps to first selection
in Menu directory (when held for three seconds)
Securiy Code
elay Menus
Each of the available relays in the 3-2551-21 and 3-2551-22 are programmed from their own
dedicated menu. See page 15 for details related to these menus.
NOMenu items associated with Relays 2 and 3 are suppressed in models without relays.
est Menu
This menu is used to manually toggle relays or to induce a known value out of the 4 to 20 mA
terminals. See page 17 for details related to this menu.
Options Menu
This menu contains those settings and values that are usually programmed during the initial
installation, and then seldom modified, including the SECURITY CODE (see section below).
See page 17 for details related to the Options menu.

9
Signet 2551 Display Magmeter
The VIEW menu contains all of the basic information available from the Magmeter.
• The normal operating display shows the FLOW RATE on the top line of the display
and the Resettable Totalizer on the lower line of the display.
• The Right Prompt symbol (>) always indicates a sub-menu associated with the
current display. In this display it points the way to the TOTALIZER RESET function.
See below for detailed instructions.
• With AUXILIARY power connected to the magmeters with Relays, the display will be
backlit. There is no switch to turn the backlight off.
• A flashing character or text on the display indicates that the item is being edited.
This manual uses a (red) star to illustrate a flashing display.
• The following information is viewed by scrolling or . These displays will remain in
the display for 10 minutes, then the normal operating display will return.
1. From the normal operating display, press the key.
3. Press any arrow key to toggle the flashing selection
from NO to YES.
4. Press the ENTER key. The totalizer will reset to all
zeroes and the display will immediately return to the
normal operating display.
2. The resettable totalizer can be configured to require
the security code before allowing the reset. If the
Total Reset is set to "RESET OFF" this display will not
appear. See page 17, Options Menu for instructions.
Show the permanent total. This totalizer cannot be reset.
This display is a reminder to visit the Signet website for updates
and information about Signet products.
Enter menus from this display. See page 10
for details.
Shows the current output. For 4 to 20 mA Output models only.
123456.78 GPM
000000.00 >
1234.56 GPM
876543.21 >
Enter Code
0000
Reset Total ?
Yes No
Gallons
Perm 876543.21
Current Output
14.89 mA
Relay 1 2 3
Off Off Off
Web Site
www.gfsignet.com
Enter Menu
>
Relay States shown for units with a relay board.
View Menu
Resetting the Resettable Totalizer
Signet Magmeter
RELAY 1 RELAY 2
ENTER
1234.56 GPM
876543.21 >
Signet Magmeter
RELAY 1 RELAY 2
ENTER
1234.56 GPM
876543.21 >

10 Signet 2551 Display Magmeter
K-Factor
060.000 >
K-Factor: See the charts on pages 12-13 for values in pulses per U.S. gallon or in pulses per liter.
To use other units, convert the published values as appropriate.
Pipe Size: Select the pipe size that is nearest to the nominal pipe size.
Averaging: Set the averaging period based on the installation and flow conditions. Smaller values
allow the 2551 to respond to changes in flow rate quickly, while larger values smooth the fluctuations
caused by installation and flow conditions. See page 11 for details.
Flow Units: Set the units for the application. Four characters are available. The first three characters can be set to any symbol or alpha
character, upper or lower case. The following special symbols are located between the upper case and lower case menus:
• (centered dot) (micro) _ (blank)
- (dash) / (slash) 3 (for cubic units)
The last character selects the timebase for the flow rate measurement.
Select S/s (seconds) M/m (minutes), H/h (hours) or D/d (days)
Total Factor: Set the factor by which the totalizer will count. This setting is made in the application
units (i.e., gallons, liters, etc.)
Totalizer Units: Set the Totalizer Units. This setting serves as a label for the totalizer displays only.
It has no effect on the measurement. The special characters listed in the Total Factor settings are
available here also.
Low Flow Cutoff: Set a flow rate that the 2551 Magmeter will use as a minimum threshhold.
If the flow rate falls below this value, the 2551 will respond as if the flow were zero.
Sensitivity: Set a percentage of maximum range by which the flow must change to override the
averaging feature and "jump" quickly to the new flow rate. See detailed explanation on page 11.
The Setup menu contains all of the parameters necessary for the 2551 Magmeter to begin
measuring flow.
NOTE: The Security Code must be entered before any changes can be made to the Setup menu.
See page 17 for details related to the Options menu..
The values shown for each menu item represent
the factory standard setting. All 2551 magmeters
are packaged with these settings.
Set 4 mA: (2551-22 and -42 versions only) Set the flow rate where the current output will be 4 mA.
Set 20 mA: (2551-22 and -42 versions only) Set the flow rate where the current output will be 20 mA.
The 4 to 20 mA output may be spanned to monitor forward and reverse flow rates.
ENTER
Pipe Size
2” DN50 >
Sensitivity
100% >
Flow Units
GPM >
Set 4 mA
-100 GPM >
Set 20 mA
100.00 GPM >
Total Factor
1000.0 >
Totalizer Units
Gallons >
Low Flow Cutoff
0.5 GPM >
Averaging
25 secs >
Use the keypad to navigate through each setting.
Enter Code
0000
Setup enu
Signet Magmeter
RELAY 1 RELAY 2
ENTER
Enter Menu
Setup >

11
Signet 2551 Display Magmeter
Sensitivity
• The SENSITIVITY setting determines how the 2551
responds to sudden surges in the flow rate. It "overrides"
the Averaging function just long enough to allow an actual
change in flow rate to be displayed, then resumes the
averaging. The result is a smooth flow display and a quick
response to large shifts in the flow rate.
The settings for Sensitivity represent a percentage of the
magmeter's maximum range, or 10 milliseconds (ms).
Example: A sensitivity setting of 25% means that the flow
rate must change instantly and by more than 2.5 ms before
the function is enabled.
NOTE: The SENSITIVITY function is ineffective if the
AVERAGING function is set to zero.
Averaging
• The AVERAGING setting dictates the time over which the
magmeter will average the flow signal.
The LCD display is updated every second. With averaging
at 14 seconds, the flow rate on the display is an average of
the previous 14 seconds input.
Short averaging times provide the fastest display and output
response to changes in the flow rate.
Higher averaging times help to smooth the display and
current output where the flow in the pipe is erratic or
unstable due to installation limitations.
No Averaging
With AVERAGING set to zero, the flow rate will be displayed
immediately and with no filtering. This line represents the
actual output of the flow sensor as it responds to unstable flow
conditions in the pipe.
10 s 20 s 30 s 40 s 50 s 60 s 70 s
Time
Velocity
Averaging Only
With AVERAGING set to 50 seconds and SENSITIVITY still
set to zero the flow rate is stabilized, but a sharp change in
flow rate is not represented on the display or at the output for
50 seconds or longer.
10 s 20 s 30 s 40 s 50 s 60 s 70 s
Time
Velocity
Averaging and Sensitivity
With AVERAGING at 50 seconds and SENSITIVITY set to
25%, the flow rate is stabilized, while the sudden shift in flow
is reflected very quickly.
10 s 20 s 30 s 40 s 50 s 60 s 70 s
Time
Velocity
Even the most carefully engineered flow systems may
experience erratic and unstable conditions. If the instability is
communicated to the output functions, the results may create
problems for control devices.
To alleviate these issues, the 2551 provides two adjustments
that operate in tandem. The information here will help
in determining the appropriate settings for any specific
application.
Averaging and Sensitivity
The SENSITIVITY function changes the
response characteristics of the magmeter.
If used as part of a tuned closed loop control
system, such a change may be undesirable.
CAUTION

12 Signet 2551 Display Magmeter
• The 2551 magmeter is designed to measure bi-directional flow.
• The forward flow direction is indicated by the directional arrow molded into the side of the 2551 sensor.
• The conduit ports are assembled at the factory to point UPSTREAM. They may be reversed by
disassembling the components of the magmeter and reassembling.
Flow Rate Display The "+" sign is suppressed during forward flow.
"-123.45 GPM" during reverse flow.
Totalizer Display The totalizer will count during forward flow conditions only.
During reverse flow the totalizer will not increment.
Relay Outputs May be set to detect reverse flow: "Low Setpoint at -25 GPM."
4 to 20 mA output May be scaled to span any flow range:
For example: "4 to 20 mA = -100 GPM to +100 GPM"
Frequency output, Frequency ÷ 10 output Reverse flow is processed same as forward flow in the frequency output magmeters.
Digital (S3L) output Reverse flow results in 0 flow rate output.
PVC Tees and Clamp-on Saddles
Pipe Size
(In.)
Fitting
Type
K-Factor
Gallons
K-Factor
Liters
SCH 80 PVC-U TEES FOR SCH 80 PIPE
½ MPV8T005 2277.0 601.58
¾ MPV8T007 1407.6 371.90
1 MPV8T010 861.17 227.52
1¼ MPV8T012 464.91 122.83
1½ MPV8T015 331.43 87.56
2 MPV8T020 192.89 50.96
SCH 80 PVC TEES FOR SCH 80 PIPE
2½ PV8T025 131.46 34.73
3 PV8T030 82.52 21.80
4 PV8T040 44.78 11.83
SCH 80 CPVC TEES FOR SCH 80 PIPE
½ MCPV8T005 2277.0 601.58
¾ MCPV8T007 1407.6 371.90
1 MCPV8T010 861.17 227.52
1¼ MCPV8T012 464.91 122.83
1½ MCPV8T015 331.43 87.56
2 MCPV8T020 192.89 50.96
SCH 80 PVC CLAMP-ON SADDLES FOR SCH 80 PIPE
2 PV8S020 193.83 51.21
2½ PV8S025 138.01 36.46
3 PV8S030 83.89 22.16
4 PV8S040 40.88 10.80
6 PV8S060 22.53 5.95
8 PV8S080 12.52 3.31
10 PV8S100 7.94 2.10
12 PV8S120 5.71 1.51
SCH 80 PVC CLAMP-ON SADDLES FOR SCH 40 PIPE
2 PV8S020 180.01 47.56
2½ PV8S025 123.72 32.69
3 PV8S030 75.81 20.03
4 PV8S040 41.87 11.06
6 PV8S060 19.71 5.21
8 PV8S080 11.73 3.10
10 PV8S100 7.43 1.96
12 PV8S120 5.23 1.38
Polypropylene True Union Tees
and Wafers
PVDF True Union Tees,
PVC True Union Tees
Pipe Size
(Metric)
Fitting
Type
K-Factor
Gallons
K-Factor
Liters
POLYPROPYLENE FITTINGS (DIN/ISO, BS, ANSI)
DN15 PPMT005 2192.73 579.32
DN20 PPMT007 1327.81 350.81
DN25 PPMT010 737.16 194.76
DN32 PPMT012 453.46 119.81
DN40 PPMT015 275.03 72.66
DN50 PPMT020 164.17 43.35
PVDF FITTINGS (DIN/ISO, BS, ANSI)
DN15 SFMT005 1946.49 514.26
DN20 SFMT007 1158.05 305.96
DN25 SFMT010 749.09 197.91
DN32 SFMT012 439.51 116.12
DN40 SFMT015 248.93 65.77
DN50 SFMT020 146.85 38.80
PVC FITTINGS (DIN/ISO, BS, ANSI)
DN15 PVMT005 2067.76 546.30
DN20 PVMT007 1136.61 300.29
DN25 PVMT010 716.52 189.31
DN32 PVMT012 446.07 117.85
DN40 PVMT015 278.83 73.67
DN50 PVMT020 159.36 42.10
Bi-Directional Flow
Calibration Data: K-Factors
Flow

13
Signet 2551 Display Magmeter
Carbon Steel Tees and Weld-o-Lets
Stainless Steel Tees and Weld-o-Lets
Galvanized Iron Tees
Pipe Size
(In.)
Fitting
Type
K-Factor
Gallons
K-Factor
Liters
CARBON STEEL TEES ON SCH 40 PIPE
½ CS4T005 1572.66 415.50
¾ CS4T007 1086.73 287.11
1 CS4T010 582.34 153.86
1¼ CS4T012 377.48 99.73
1½ CS4T015 267.79 70.75
2 CS4T020 167.85 44.35
STAINLESS STEEL TEES ON SCH 40 PIPE
½ CR4T005 1601.26 423.05
¾ CR4T007 937.78 247.76
1 CR4T010 606.18 160.15
1¼ CR4T012 279.68 73.89
1½ CR4T015 147.65 39.01
2 CR4T020 111.90 29.56
STAINLESS STEEL WELDOLETS ON SCH 40 PIPE
2½ CR4W025 106.31 28.09
3 CR4W030 72.27 19.09
4 CR4W040 36.84 9.73
5 CR4W050 29.28 7.73
6 CR4W060 20.29 5.36
8 CR4W080 11.73 3.10
10 CR4W100 7.45 1.97
12 CR4W120 5.24 1.39
CARBON STEEL WELDOLETS ON SCH 40 PIPE
2½ CS4W025 105.70 27.93
3 CS4W030 70.68 18.67
4 CS4W040 36.38 9.61
5 CS4W050 29.28 7.73
6 CS4W060 20.29 5.36
8 CS4W080 11.73 3.10
10 CS4W100 7.45 1.97
12 CS4W120 5.24 1.39
GALVANIZED IRON TEES ON SCH 40 PIPE
1 IR4T010 558.50 147.56
1¼ IR4T012 334.45 88.36
1½ IR4T015 248.97 65.78
2 IR4T020 146.00 38.57
Bronze and Copper Tees and Brazolets
Pipe Size
(In.)
Fitting
Type
K-Factor
Gallons
K-Factor
Liters
BRONZE TEES ON SCH 40 PIPE
1 BR4T010 582.34 153.86
1¼ BR4T012 330.54 87.33
1½ BR4T015 254.76 67.31
2 BR4T020 157.36 41.58
COPPER TEES FITTING ON COPPER PIPE SCH K
½ CUKT005 2459.19 649.72
¾ CUKT007 1108.02 292.74
1 CUKT010 649.87 171.70
1¼ CUKT012 422.03 111.50
1½ CUKT015 281.43 74.35
2 CUKT020 136.02 35.94
COPPER TEES FITTING ON COPPER PIPE SCH L
½ CUKT005 2406.30 635.75
¾ CUKT007 1174.77 310.37
1 CUKT010 672.28 177.62
1¼ CUKT012 402.84 106.43
1½ CUKT015 294.99 77.94
2 CUKT020 149.63 39.53
COPPER/BRONZE BRAZOLET ON SCH 40 PIPE
2½ BR4B025 117.31 30.99
3 BR4B030 78.62 20.77
4 BR4B040 45.13 11.92
5 BR4B050 32.79 8.66
6 BR4B060 22.73 6.01
8 BR4B080 13.14 3.47
10 BR4B100 8.34 2.20
12 BR4B120 5.87 1.55
Iron Saddles
Pipe Size
(In.)
Fitting
Type
K-Factor
Gallons
K-Factor
Liters
SCH 80 IRON SADDLE ON SCH 80 PIPE
2 IR8S020 194.85 51.48
2½ IR8S025 142.28 37.59
3 IR8S030 87.53 23.13
4 IR8S040 40.62 10.73
5 IR8S050 29.28 7.74
6 IR8S060 22.30 5.89
8 IR8S080 12.52 3.31
10 IR8S100 7.94 2.10
12 IR8S120 5.65 1.49
SCH 80 IRON SADDLE ON SCH 40 PIPE
2 IR8S020 185.35 48.97
2½ IR8S025 127.47 33.68
3 IR8S030 76.62 20.24
4 IR8S040 40.23 10.63
5 IR8S050 27.32 7.22
6 IR8S060 19.71 5.21
8 IR8S080 11.61 3.07
10 IR8S100 7.36 1.94
12 IR8S120 5.18 1.37
Calibration Data: K-Factors

14 Signet 2551 Display Magmeter
The K-Factors published in this manual assume that the flow conditions in the pipe are ideal.
Many factors that affect the flow rate are beyond the control of the magmeter; variations in actual
pipe dimensions, pipe smoothness, and other flow conditions will contribute to the total system error.
Performing a custom calibration with the magmeter in place will adjust the K-Factor and can serve
to compensate for installation conditions that may be less than ideal.
Select one of the calibration methods in this menu to achieve the most accurate measurement
possible in a specific application.
Use this method if the 2551 Magmeter must be calibrated to match a reference flow meter. This is the method most commonly used
by monitoring agencies, and for large pipes where volumetric calibration is impractical. The accuracy of this calibration method is
largely dependent on the accuracy of the reference meter and the proximity of the reference to the Signet 2551 Magmeter.
Use the volume method of calibration if the fluid passing the magmeter can be measured by a volumetric method (as in a vessel of
known volume, or by weight). It requires the ability to pump a known volume of water past the magmeter, and then input the volume
into the 2551 program. It is most useful for small pipes and lower flow rates.
When performed properly, volumetric calibration is the most accurate method. For best results a five minute test period is
recommended, and the test period should be no less than two minutes.
At START, the 2551 begins counting the flow past the sensor.
At STOP, the 2551 stores the total flow accumulated since the START.
Enter the VOLUME that has been pumped past the sensor.
This error message appears if volume entered or the accumulated flow is zero.
Repeat the test after checking the system.
Press Enter
To Start
Enter Volume
000000. GPM
K-Factor
45.6789
Value must be
more than 0.0
K-Factor
Out of Range
Press Enter
To Stop
Using the information from the VOLUME method, the 2551 will recalculate a new K-Factor.
Press ENTER to accept the new value, or use the keypad to adjust the value.
This message appears if the new K-Factor is less than 0.0001 or greater than 999999.
To correct the problem, perform the volumetric flow again, and be certain that the
volume entered is accurate.
3s
ENTER
Or
Signet Magmeter
RELAY 1 RELAY 2
ENTER
1234.56 GPM
876543.21 >
Enter Menu
>
Enter Menu
Setup >
Enter Menu
Calibration >
Using the information from the RATE MATCHING method, the 2551 will recalculate a new K-Factor.
Press ENTER to accept the new value, or use the keypad to adjust the value.
The flow rate shown is based on the existing calibration of the 2551. Use the keypad to modify
the flow rate to match the reference meter. The 2551 will automatically calculate a new K-Factor
based on the new flow rate.
This message appears if the new K-Factor is less than 0.0001 or greater than 999999.
To correct the problem, reexamine the flow rate and make certain it is accurate.
Set New Flowrate
45.6789
K-Factor
56.7890
K-Factor
Out of Range
Enter Code
0000
NOTE: The Security Code must be entered
before selecting the calibration method.
Calibration Menu
Rate Method of Calibration
Volume Method of Calibration

15
Signet 2551 Display Magmeter
Magmeter models 3-2551-21 and -22 have two dry contact relays (Relays 1 and 2) and one Solid
State relay (Relay 3).
Any of these relays can be set to any of the operating modes listed below.
The setpoint values for HIGH, LOW and WINDOW modes can be set to negative values if required.
For example, a LOW alarm might be set to activate if the flow rate falls below -10 GPM.
Negative values are not available for relays in PULSE or TOTAL modes.
Off: If a relay is not used, it can be turned Off to prevent contact wear.
Program a relay to activate when the Resettable totalizer reaches a specific value. The maximum setting is 999999.
Application example: A filter must be replaced in an R.O. system every 10000 gallons. The service representative that installs
a new filter sets relay 3 to Total mode, sets the setpoint at 10000 and resets the totalizer to 000000.00. Every time the Totalizer
reaches 10000, the relay activates and lights a message indicator to remind the service representative to replace the filter.
When the totalizer is reset, the relay will be deactivated and the process begins anew.
Program a relay to activate for a fixed period, for each volume of fluid that passes the sensor.
For example, program the relay to pulse once for 100 ms for every 3 gallons that pass by the sensor.
Relay 1 Mode
Pulse >
Relay 1 Width
0.1 secs >
Relay 1 Volume
0.0000 Gal >
Relay Volume: Set the volume of fluid that the 2551 must
measure before activating the relay for one pulse.
Pulse Width: Adjust the length of time the relay will remain
activated. The pulse width setting is dependent on the type of
external equipment being connected to the relay.
Relay 1 Mode
Total >
Relay 1 Set High
000000 >
3s
ENTER
Or
Signet Magmeter
RELAY 1 RELAY 2
ENTER
1234.56 GPM
876543.21 >
Enter Menu
>
Enter Menu
Setup >
Enter Menu
Calibration >
Enter Menu
Relay 1 >
NOTE: The Security Code must be entered
before modifying the relay menu.
Enter Code
0000
Relay Menus
Pulse Relay Mode
Total Relay Mode

16 Signet 2551 Display Magmeter
The values shown for each menu item represent the factory standard
setting. All 2551 magmeters are packaged with these settings.
Hysteresis
Time
Low Setpoint
Process
Relay activated
Relay deactivated
Hysteresis
Time
High Setpoint
Process
High Limit Hysteresis
Hysteresis
Window
Time
Low Limit
Process
Program the relay to activate when the flow rate reaches a setpoint (High or Low) or when the flow
rate moves outside of a prescribed range (Window).
Reverse Flow
The setpoint values for HIGH, LOW and WINDOW modes can be set to negative values if required.
For example, a LOW alarm might be set to activate if the flow rate falls to -10 GPM.
The menu repeats for Relay 2 and Relay 3.
Set High:
Set the flow rate where a High relay will be activated.
Set Low:
Set the flow rate where a Low relay will be activated.
Hysteresis:
Set a flow rate increment where the relay will be deactivated.
The hysteresis setting serves to prevent relay "chatter" when
the flow rate recovers from an alarm condition by requiring the
low rate to move substantially within the setpoint.
Delay:
Set a time period for the relay to wait after reaching the setpoint.
This delay serves to prevent the relay "chatter" by allowing the
flow rate time to move back within the setpoint.
Relay 1 Mode
Low >
Relay 1 Mode
High >
Relay 1 Mode
Window >
Relay 1 Set Low
00.000 GPM >
Relay 1 Set High
00.000 GPM >
Relay 1 Set Low
00.000 GPM >
Relay 1 Hys
00.000 GPM >
Relay 1 Delay
0.1 secs >
Relay 1 Set High
00.000 GPM >
Relay 1 Hys
00.000 GPM >
Relay 1 Delay
0.1 secs >
Relay 1 Hys
00.000 GPM >
Relay 1 Delay
0.1 secs >
3s
ENTER
Or
Signet Magmeter
RELAY 1 RELAY 2
ENTER
1234.56 GPM
876543.21 >
Enter Menu
>
Enter Menu
Setup >
Enter Menu
Calibration >
Enter Menu
Relay 1 >
Enter Code
0000
NOTE: The Security Code
must be entered before
modifying the relay menu.
Relay behavior with LOW Setpoint
Relay behavior with HIGH Setpoint
Relay behavior with WINDOW Setpoints
High, Low, or Window Relay Modes

17
Signet 2551 Display Magmeter
The Options Menu contains those features and settings that will normally be set one time and then seldom changed. These include
language preference, decimal placement, Security Code assignment, etc.
Language
English >
Security Code
**** >
Contrast
2 >
Total Reset
Lock On >
Noise Rejection
60 Hz >
Flow Decimal
****.** >
Total Decimal
******.** >
Separator
ddd.d >
Output Mode
Frequency >
Select from English, French, German, Italian, Portuguese or
Spanish. This selection will be displayed at first power-up of a
new magmeter.
Security Code can be set to any four digit number.
Factory standard setting is 0000.
Set for best view after the magmeter is installed.
Larger number means display appears darker.
Lock ON requires the Security Code before resetting the
Resetable Totalizer. Lock OFF reset with no security code.
Filters out common 50 or 60 Hz electrical noise.
Set the maximum resolution for the FLOW RATE display by
limiting the decimal to this point. The Flow Rate display will
auto-scale from this resolution up to whole units.
Set the maximum resolution for the TOTALIZER display by
limiting the decimal to this point. The Totalizer display will
always show this resolution.
Select decimal point or comma for use in numeric displays.
For Frequency/Digital models only: Select Freq output,
Freq ÷ 10 output, Mirror Relay 1 output or (S3L) Digital output.
In FREQUENCY output mode, the 2551 serves as a traditional flow sensor and provides an output pulse that is compatible
with all Signet POWERED flow instruments. It is not compatible with the 5090 Self-Powered Flow Meter or the 8150-1 Battery-
Powered Flow Totalizer. The frequency output range is from 0 Hz to 1000 Hz.
The FREQUENCY ÷ 10 output mode reduces the output frequency of the 2551 to a range that is useful for some programmable
logic controllers (PLC). The frequency output range is from 0 Hz to 100 Hz. This shift does not affect the stated accuracy of the
2551 Magmeter's frequency output.
The MIRROR RELAY 1 output mode allows 2551 Frequency/Digital models to use the Open Collector Output like a relay that can
be programmed via the Relay 1 menu. If the magmeter is equipped with relays, this mode will mirror the settings of Relay 1.
If the magmeter is not equipped with relays, this mode can still be selected and programmed via the Relay 1 menu.
The (S3L) Digital output mode switches the 2551 to the Signet serial data output called (S3L) (Signet Serial Sensor Link).
In this mode the 2551 can be added to the serial bus of the Signet 8900 Multi-Parameter Controller or 9900 Transmitter.
The Test menu provides a simple method to verify that the system is operating properly. Auxiliary power MUST be connected to the
2551 to activate the relays
Test Output
4.20 mA >
Test Relay 1
Open Closed >
Test Relay 2
Open Closed >
Test Relay 3
Open Closed >
The values shown for each
menu item represent the
factory standard setting.
All 2551 magmeters are
packaged with these settings.
Shown for 4 to 20 mA models only (3-2551-XX-22, -42).
Use the keypad to enter any current output from 4.0 mA
minimum to 22.1 mA maximum.
Shown for Relay models Only
Toggle any of these relays ON and OFF to verify that the
system is operating properly.
V+
V–
Auxiliary Power
9 to 24 VDC
0.4 A Maximum
Auxiliary power MUST be
connected to the 2551 to
test the relays.
Test Menus
Output Modes
Options Menus
Signet Magmeter
RELAY 1 RELAY 2
ENTER
Enter Menu
Options >
Signet Magmeter
RELAY 1 RELAY 2
ENTER
Enter Menu
Test >

18 Signet 2551 Display Magmeter
Grounding rings on plastic pipe
(Install between flanges)
or
metal stra
p
s on metal
p
i
p
e
Sensor
Grounding ring
(10 cm to 1.3 m) (10 cm to 1.3 m)
4 in. to 50 in. 4 in. to 50 in.
Instrument
4.
2.2.
Do not terminate
shield at Magmeter
3.
1.
Precalibration conditioning: The magmeter may appear to be unstable immediately after installation. Allow the sensor to sit in a full
pipe for 24 hours before beginning calibration and operation.
• Use a cable gland or a liquid tight connector to seal the cable ports from water intrusion.
• Use PTFE tape or a suitable sealant on cable ports.
• The 2551 magmeter must be carefully grounded to eliminate electrical noise that may interfere with the measurement.
• Grounding requirements will vary with each installation.
• The following recommendations should be applied in sequence until the interference is eliminated.
The ground terminal on the outside of the yellow housing is connected internally to the grounding ring at the tip of the sensor.
Connect a conductor (14 AWG/1.5 mm2 wire recommended) from this terminal directly to Earth ground to prevent electrical
noise from interfering with the magmeter signal.
If the interference persists, apply step #2:
Connect grounding rings, metal clamps or grounding electrodes to the pipe immediately upstream and downstream of the
magmeter sensor location. These devices must be in contact with the fluid.
If the interference persists, apply step #3:
The shield from the output cable must be terminated at the remote instrument ONLY.
This shield must not be connected at both ends!
If the interference persists, apply step #4:
Connect an additional wire (minimum AWG 14/1.5 mm2) from the remote instrument ground to the magmeter ground terminal.
Environmental Recommendations:
• When used properly, this product presents no inherent danger to the environment.
• Please follow local ordinance when disposing of this or any product with electronic components.
The 2551 Magmeter requires very little maintenance. There are no user-serviceable components in the magmeter.
• If the fluid contains deposits and solids that may coat the electrodes, a regular cleaning regimen is recommended.
• Do not use abrasive materials on the metal electrodes. Clean with soft cloth and mild detergent only.
• Use a cotton swab and mild detergent to remove deposits on the metal electrodes.
Grounding
Maintenance

19
Signet 2551 Display Magmeter
Troubleshooting with the RED and BLUE LEDs
No Lights: The power is off or the sensor is not connected
Solid Blue: The power is on but there is no flow in the pipe.
Blinking Blue: Normal operation, blink rate is proportional to the flow rate.
Alternating Red-Blue: Empty pipe indication (electrodes are not wet.)
Blinking Red: System errors (Electrical noise interference)
Solid Red: Instrument error (defective electronic component)
Reverse flow:
• Frequency out cannot distinguish reverse flow from forward flow. The output will be the absolute value.
• Digital (S3L) output: Reverse flow results in 0 flow rate displayed on 8900, or with negative numbers on the 9900.
• 4 to 20 mA output can be spanned into negative flow range using the custom setup tool. (example: 4 to 20 mA = -100 to +100 GPM).
Empty Pipe Detection
• Frequency output will be locked to 0 Hz if electrodes are not wet.
• Digital (S3L) output will be locked to 0 if electrodes are not wet.
• 4 to 20 mA will be locked to 4 mA if electrodes are not wet.
• Blue and Red LED indicators on the magmeter circuit will blink alternately if the electrodes are not wet.
Symptom Possible Cause Solution
Output is erratic and unstable.
Magmeter installed too close to upstream
obstruction.
Relocate the magmeter to have straight
uninterrupted pipe upstream of the sensor
for at least 10 x the pipe diameter.
Magmeter located in area exposed to air
bubbles/pockets. Eliminate air bubbles in the pipe.
Magmeter is installed in pipe backwards.
Remove the magmeter and reinstall with
the flow direction arrow on the sensor body
pointed DOWNSTREAM.
Electrical noise is interfering with the
measurement.
Review the grounding of the magmeter and
the pipe. Install adequate Earth ground to
allow the Magmeter to operate properly.
Electrodes are coated with deposits or
chemical oxide layers.
Carefully clean the electrodes. Refer to
sensor manual for details.
Output is not 0 when flow is stopped.
Electrodes not adequately conditioned in
fluid.
Allow the sensor to sit in full pipe for
24 hours then restart.
Fluid is moving inside the pipe. Increase the Low Flow Cutoff. (page 10)
No 4 to 20 mA output. Loop power not connected correctly. Connect 24 VDC ±10% connected to loop
terminals 1 and 3.
4 to 20 mA current output is incorrect. 4 to 20 mA is not scaled properly. Check and reset in the Setup Menu.
No Frequency output.
No (S3L) output.
2551 is wrong model. Frequency / (S3L) model:
3-2551-21 (w/rlys) or -41 (w/o rlys).
Incorrect setting in Options Menu. Select Frequency in the Options menu.
Wiring is not correct. Check wiring, make corrections.
Frequency input to other manufacturer's
flow instrument does not have pull-up
resistor.
Install 10 kresistor. (page 6)
No flow rate, current output is 22 mA. The fluid is too clean for Magmeter. Unsuitable application for Magmeter.
Electronic component failure. Return 2551 to factory.
Blank display, no backlighting, no relay
LEDs, but external equipment using
output signal is still working.
2551 AUX power is not connected. Connect AUX power (page 7)
(9 to 24 VDC, 0.4 A max.)
Error Message:
"Error Not Saved" Main power is below specification. Correct the main power deficiency.
Troubleshooting
1
2
D7
D6

Ordering Information
Georg Fischer Signet LLC, 3401 Aero Jet Avenue, El Monte, CA 91731-2882 U.S.A. • Tel. [phone] • Fax [phone]
For Worldwide Sales and Service, visit our website: www.gfsignet.com • Or call (in the U.S.): [phone]
For the most up-to-date information, please refer to our website at www.gfsignet.com
3-2551.090-1 Rev. M 04/15 English © Georg Fischer Signet LLC 2015
Mfr. Part No. Code Description
3-2551-P0-21 159 001 267 DN15 to DN100 (½ in. to 4 in.) Polypropylene and 316L SS. Two SPDT relays, one solid state relay
3-2551-T0-21 159 001 436 DN15 to DN100 (½ in. to 4 in.) PVDF and Titanium. Two SPDT relays, one solid state relay
3-2551-V0-21 159 001 269 DN15 to DN100 (½ in. to 4 in.) PVDF and Hastelloy-C. Two SPDT relays, one solid state relay
3-2551-P0-41 159 001 261 DN15 to DN100 (½ in. to 4 in.) Polypropylene and 316L SS.
3-2551-T0-41 159 001 433 DN15 to DN100 (½ in. to 4 in.) PVDF and Titanium
3-2551-V0-41 159 001 263 DN15 to DN100 (½ in. to 4 in.) PVDF and Hastelloy-C
3-2551-P1-21 159 001 268 DN125 to DN200 (5 in. to 8 in.) Polypropylene and 316L SS. Two SPDT relays, one solid state relay
3-2551-T1-21 159 001 437 DN125 to DN200 (5 in. to 8 in.) PVDF and Titanium. Two SPDT relays, one solid state relay
3-2551-V1-21 159 001 270 DN125 to DN200 (5 in. to 8 in.) PVDF and Hastelloy-C. Two SPDT relays, one solid state relay
3-2551-P1-41 159 001 262 DN125 to DN200 (5 in. to 8 in.) Polypropylene and 316L SS
3-2551-T1-41 159 001 434 DN125 to DN200 (5 in. to 8 in.) PVDF and Titanium
3-2551-V1-41 159 001 264 DN125 to DN200 (5 in. to 8 in.) PVDF and Hastelloy-C
3-2551-P2-21 159 001 435 DN250 to DN900 (10 in. to 36 in.) Polypropylene and 316L SS. Two SPDT relays, one solid state relay
3-2551-T2-21 159 001 454 DN250 to DN900 (10 in. to 36 in.) PVDF and Titanium. Two SPDT relays, one solid state relay
3-2551-V2-21 159 001 456 DN250 to DN900 (10 in. to 36 in.) PVDF and Hastelloy-C. Two SPDT relays, one solid state relay
3-2551-P2-41 159 001 432 DN250 to DN900 (10 in. to 36 in.) Polypropylene and 316L SS
3-2551-T2-41 159 001 460 DN250 to DN900 (10 in. to 36 in.) PVDF and Titanium
3-2551-V2-41 159 001 462
DN250 to DN900 (10 in. to 36 in.) PVDF and Hastelloy-C
Mfr. Part No. Code Description
3-2551-P0-22 159 001 273 DN15 to DN100 (½ in. to 4 in.) Polypropylene and 316L SS. Two SPDT relays, one solid state relay
3-2551-T0-22 159 001 439 DN15 to DN100 (½ in. to 4 in.) PVDF and Titanium. Two SPDT relays, one solid state relay
3-2551-V0-22 159 001 275 DN15 to DN100 (½ in. to 4 in.) PVDF and Hastelloy-C. Two SPDT relays, one solid state relay
3-2551-P0-42 159 001 279 DN15 to DN100 (½ in. to 4 in.) Polypropylene and 316L SS.
3-2551-T0-42 159 001 442 DN15 to DN100 (½ in. to 4 in.) PVDF and Titanium
3-2551-V0-42 159 001 281 DN15 to DN100 (½ in. to 4 in.) PVDF and Hastelloy-C
3-2551-P1-22 159 001 274 DN125 to DN200 (5 in. to 8 in.) Polypropylene and 316L SS. Two SPDT relays, one solid state relay
3-2551-T1-22 159 001 440 DN125 to DN200 (5 in. to 8 in.) PVDF and Titanium. Two SPDT relays, one solid state relay
3-2551-V1-22 159 001 276 DN125 to DN200 (5 in. to 8 in.) PVDF and Hastelloy-C. Two SPDT relays, one solid state relay
3-2551-P1-42 159 001 280 DN125 to DN200 (5 in. to 8 in.) Polypropylene and 316L SS
3-2551-T1-42 159 001 443 DN125 to DN200 (5 in. to 8 in.) PVDF and Titanium
3-2551-V1-42 159 001 282 DN125 to DN200 (5 in. to 8 in.) PVDF and Hastelloy-C
3-2551-P2-22 159 001 438 DN250 to DN900 (10 in. to 36 in.) Polypropylene and 316L SS. Two SPDT relays, one solid state relay
3-2551-T2-22 159 001 455 DN250 to DN900 (10 in. to 36 in.) PVDF and Titanium. Two SPDT relays, one solid state relay
3-2551-V2-22 159 001 457 DN250 to DN900 (10 in. to 36 in.) PVDF and Hastelloy-C. Two SPDT relays, one solid state relay
3-2551-P2-42 159 001 441 DN250 to DN900 (10 in. to 36 in.) Polypropylene and 316L SS
3-2551-T2-42 159 001 461 DN250 to DN900 (10 in. to 36 in.) PVDF and Titanium
3-2551-V2-42 159 001 463
DN250 to DN900 (10 in. to 36 in.) PVDF and Hastelloy-C
Replacement Parts and Accessories
1220-0021 198 801 186 O-ring, FPM
1224-0021 198 820 006 O-ring, EPDM
1228-0021 198 820 007 O-ring, FFPM
3-8050.390-1 159 001 702 Retaining Nut Replacement Kit, NPT, Valox®
3-8050.390-3 159 310 116 Retaining Nut Replacement Kit, NPT, PP
3-8050.390-4 159 310 117 Retaining Nut Replacement Kit, NPT, PVDF
3-8050.396 159 000 617 RC Filter kit (for relay protection)
3-8551.521 159 001 378 Clear plastic cap for display
Frequency or Digitial (S3L) output
4 to 20 mA output