Dwyer Instruments Series DH3 Digihelic User manual

Bulletin B-30
Series DH3 Digihelic®Differential Pressure Controller
Specifications - Installation and Operating Instructions
DWYER INSTRUMENTS, INC. Phone: [phone] www.dwyer-inst.com
P.O. BOX 373 • MICHIGAN CITY, IN 46361, U.S.A. Fax: [phone] e-mail: [e-mail]

2
SPECIFICATIONS
Service: Air and non-combustible,
compatible gases.
Wetted Materials: Consult factory.
Housing Material: Die cast aluminum
case and bezel.
Accuracy: < 5˝ w.c. (except ±2.5˝ w.c.)
: ±1%; All other ranges: ±0.5% at 77°F
(25°C) including hysteresis and repeata-
bility (after 1 hour warm-up).
Stability: < ±1% per year.
Pressure Limits: Ranges
≤2.5˝ w.c.: 25 psi; ±2.5”, 5˝w.c.: 5 psi;
10˝:w.c. 5 psi; 25˝w.c.: 5 psi; 50˝w.c.: 5
psi; 100˝w.c.: 9 psi.
Temperature Limits: 32 to 140°F (0 to
60°C).
Compensated Temperature Limits:
32 to 140°F (0 to 60°C).
Thermal Effects: 0.020%/°F
(0.036/°C) from 77°F (25°C).
Power Requirements: 12-24
VAC/VDC.
Power Consumption: 3 VA max.
Output Signal: 4-20 mA DC into 900
ohms max.
Zero & Span Adjustments:
Accessible via menus.
Response Time: 250 ms (dampening
set to 1).
Display: Backlit 4 digit LCD 0.4˝ height
LED indicators for set point and alarm
status.
Electrical Connections: 15 pin male
high density D-Sub connection. 18˝ (46
cm) cable with 10 conductors included.
Process Connections: 1/8˝ female
NPT. Side or back connections.
Mounting Orientation: Mount unit in
vertical plane.
Size: 5˝ (127 mm) O.D. x 3-1/8˝ (79.38
mm).
Weight: 1.75 lbs. (794 g).
Agency Approvals: CE.
Switch SPECIFICATIONS
Switch Type: 2 SPDT relays.
Electrical Rating: 1 amp @ 30
VAC/VDC.
Set Point Adjustment: Adjustable via
keypad on face.
DIMENSIONS
(4) 6-32 HOLES
EQUALLY SPACED ON A
5-1/8 (130.18) B.C.
PANEL MOUNTING
1/8 FEMALE NPT LOW
PRESSURE CONNECTION
1/8 FEMALE NPT HIGH
PRESSURE CONNECTION
2-1/16
(52.39)
2
(50.80)
1-1/4
(31.75) ø4-47/64
(120.25) Ø5
(127.00)
Ø4 (101.60)
FACE
5-1/2 (139.70) O.D.
MOUNTING RING
5/8 (15.88)
PANEL MAX
2-1/2
(63.50)
3/16
(4.76)
1/8 FEMALE NPT HIGH
PRESSURE CONNECTION
1/2
(12.70)
1-9/32
(32.54)
11/16
(17.46)
30°
1-3/4
(44.45)
1/2 (12.70)
11/16
(17.46)
1/8 FEMALE NPT LOW
PRESSURE CONNECTION
(3) Ø3/16 (4.77) HOLES EQUALLY
SPACED ON A 4-1/8 (104.78) B.C.
SURFACE MOUNTING

INSTALLATION
LOCATION:Select a clean, dry location free from shock and vibration where tem-
perature limits will not be exceeded. Distance from the transmitter to the receiver is
limited only by total loop resistance. See ELECTRICAL CONNECTIONS. Tubing
feeding pressure to the instrument can be practically any length required, but long
lengths will increase response time slightly.
POSITION: All standard models are calibrated for use in a vertical mounting posi-
tion. Higher range models will perform properly at other angles but should be
spanned and zeroed in the position in which they will be used. Because of their sen-
sitivity to gravitational forces, models with ranges under 1″w.c. (25.4 mm w.c.) must
always be mounted vertically.
PRESSURE CONNECTIONS: For installation convenience two sets of 1/8″female
NPT pressure ports are supplied. Be sure to seal the unused ports with pipe plugs
included.
Positive Pressure - Connect tubing to HIGH PRESSURE port and vent LOW
PRESSURE port to atmosphere.
Negative (Vacuum) Pressure - Connect tubing to LOW PRESSURE port and vent
HIGH PRESSURE port to atmosphere. (When operating this device in a dusty envi-
ronment, install an optional A-331 Filter Vent Plug in the vented port to keep interi-
or clean.)
Differential Pressure - Connect tubing from the higher source to HIGH PRES-
SURE port and from the lower source to LOW PRESSURE port.
3
1-1/2
[38.1]
5/16
[7.94] 11/16
[17.46]
3/4
[19.05]
1-3/32
[27.78]
1-3/4
[44.45]
1/2 [12.70]
(3) Ø3/16 [4.77] HOLES EQUALLY
SPACED ON A 4-1/8 [104.78] B.C.
Ø1/2 [12.70] HOLE FOR
LOW PRESSURE CONNECTION
Ø1/2 [12.70] HOLE FOR
HIGH PRESSURE CONNECTION
Fig. A

4
MOUNTING: The DH 3 may be either panel (flush) mounted or surface mounted.
Panel Mounting - Cut a 4-13/16″or 122 mm diameter hole in the panel and insert
the unit from the front. Slip on the mounting ring with the stepped side facing rear.
Next, fit the snap ring into the narrow groove at back edge of bezel. Thread four (6)
32 x 1-1/4″mounting screws into tapped holes in mounting ring and set it against
snap ring. Tighten screws against rear of panel. See Fig. B.
Surface Mounting - Drill (3) 3/16″(4.76 mm) diameter holes for mounting and cut
a 9/16″x 1-1/2″(14.3 x 38.1 mm) opening for access to terminal block as indicat-
ed in Fig. B. If rear pressure connections are to be used, also provide 1/2″diameter
holes as shown in Figs. A and C. Insert 6-32 machine screws from rear of mounting
surface, thread into tapped holes on back of transmitter and tighten.
Fig. B
Fig. C
Ø4-3/4 [120.65] HOLE
PNEUMATIC
PRESSURE TAPS
SNAP RING
GROOVE

WIRING
The DH 3 uses a standard 15 pin male high density D-Sub connector available
from most electronic distributors. A pre-wired 18˝ cable is included with each unit.
See below table for cable color wiring information.
NOTES:
1. If 12-24 VDC power is used, the polairty is unimportant.
2. Wire in accordance with an equivalent national standard or code. Use copper
conductors only rated for 60°C.
3. All terminals are rated CLASS 2.
4. ISOLATION: All inputs and outputs to each other: 500 VAC.
5. 4-20 mA Transmitter – Check the specifications for the device receiving this sig-
nal for input resistance. Typical 250 to 600 OHMS, 600 OHMS maximum.
5
FUNCTION
12-24 VAC/VDC POWER
12-24 VAC/VDC POWER
4-20mA XMTR OUTPUT -
4-20mA XMTR OUTPUT +
SP1 RELAY N/O
SP1 RELAY COM
SP1 RELAY N/C
SP2 OR ALARM RELAY N/O
SP2 OR ALARM RELAY COM
SP2 OR ALARM RELAY N/C
15 PIN CONNECTOR
TERMINAL
1
6
2
11
12
13
14
15
10
5
CABLE COLOR
BROWN
YELLOW
BLACK
RED
VIOLET
GREY
WHITE
BLUE
GREEN
ORANGE

6
SP/ALSP/AL
MENUMENU
EE
RSTRST
SP/ALSP/AL
MENUMENU
EE
RSTRST
SP/ALSP/AL
MENUMENU
EE
RSTRST
SP/ALSP/AL
MENUMENU
EE
RSTRST
SP/ALSP/AL
MENUMENU
EE
RSTRST
SP/ALSP/AL
MENUMENU
EE
RSTRST
HOME POSITION FUNCTION
Sequences the display
through SET POINT and
ALARM settings
Allows access to the
menus
Displays full scale
range of unit
Clears or resets an Alarm
(alarm set for manual
reset)
MAIN MENU FUNCTION
Return to home
position
Return to home
position
Sequences through
menus
Sequences through
menus
Enter into SUB MENU
SUB MENU FUNCTION
Return to home position
Return to previous menu
Increments a value
Decrements a value
Changes a value or
setting. Press ENTER
and display will blink.
Adjust with UP or DOWN
arrows. Press ENTER to
store. Display will stop
blinking.
Peak/Valley SUB
MENU resets display to
present value.
SP/AL
MENU
UP
ARROW
DOWN
ARROW
ENTER
RESET
KEY FUNCTIONS
INWCINWC
1.0001.000
SP1SP1 SP2SP2
ALHIALHI
ALLOALLO
SP/ALSP/AL
RSTRST
MENUMENU
EE
X1KX1K
FRONT PANEL
ALARM
DESCRIPTOR
UNITS
INPUT VALUE
MULTIPLIER
DESCRIPTOR
VISABLE WITH
SOME VELOCITY
AND FLOW
RANGES
SP2 DESCRIPTOR
SP1 DESCRIPTOR

7
SETTING SET POINTS AND ALARMS
The hot key provides direct access to the Set Point and Alarm MENU. The
Set Point and Alarm MENUS that are displayed are based upon the Control (CtrL)
SUB MENU.
SP/ALSP/AL SP/ALSP/AL SP/ALSP/AL
SP/ALSP/AL SP/ALSP/AL SP/ALSP/AL
SP/ALSP/AL SP/ALSP/AL
SP/ALSP/AL SP/ALSP/AL SP/ALSP/AL
SP/ALSP/AL SP/ALSP/AL
Visible whenVisible when
Visible whenVisible when
Visible whenVisible when
mode =mode =
mode =mode =
mode =mode =
CONTROL MODECONTROL MODE CONTROL MODECONTROL MODE
CONTROL MODECONTROL MODE
SET POINT ADJUSTMENT
Adjusting the DH®3 Set Points is quick and simple. Instead of setting a set point and
deadband, simply adjust SP1H or SP2H for the desired relay turn on point, and
then adjust SP1L or SP2L for the desired relay turn off point.
PRESSURE
PRESSURE
00
00TIMETIME
0.20.2
0.40.4
0.60.6
0.80.8
1.0
(in. w.c.)
In the above graph, an instrument with a 1.0˝ range would have the SP1 relay turn
on at 0.8˝ and off at 0.4˝.
SP1H sets the relay turn on point, and SP1L sets the relay
turn off point. The relays outputs normally function in the direct acting mode, which
means the relays turn on with an increase in pressure. SP1 may be configured to act
as a reverse acting relay (refer to the 1SP SUB MENU setting, page 15). When set
for reverse acting,
SP1H sets the relay turn OFF point, and SP1L sets the relay turn
ON point. SP2 is always direct acting.
SP/ALSP/AL

8
MENU MAPMENU MAP
CONTINUED
CONTINUED
SETTINGSSETTINGS
MAIN MENUS SUB MENUS
MENUS
UNAVAILABLE
FOR
BI-DIRECTIONAL
RANGES AND
RANGES ABOVE
25 IN. W.C.
SP/ALSP/AL
MENUMENU
EE
RSTRST
SP/ALSP/AL
MENUMENU
EE
RSTRST
SP/ALSP/AL
MENUMENU
EE
SP/ALSP/AL
MENUMENU

9
CONTINUEDCONTINUED
SETTINGSSETTINGS
MAIN MENUS SUB MENUS
0PEn
SP/ALSP/AL
MENUMENU
EE
RSTRST
SP/ALSP/AL
MENUMENU
EE
RSTRST
SP/ALSP/AL
MENUMENU
EE
SP/ALSP/AL
MENUMENU

10
MAIN MENUS SUB MENUS SETTINGS
Menus present only
in pressure operation
SP/ALSP/AL
MENUMENU
EE
RSTRST
SP/ALSP/AL
MENUMENU
EE
RSTRST
SP/ALSP/AL
MENUMENU
EE
RSTRST
SP/ALSP/AL
MENUMENU
EE
RSTRST

11
Main Menu Selections (Upper Right Display Reads MENU )
SECr Security - Lock out access to Set Point and Alarm settings, or lock out
access to all settings.
OPEr Operation - Selection of Pressure, Velocity or Flow and corresponding
engineering units.
OUt Output - Select a Single Set Point, 2 Set Points, or a Set Point and an
Alarm mode of operation.
d.S Display - Monitor and adjust display related settings: Peak, Valley, display
resolution, % output and dampening.
AdU Advanced functions - Modify advanced function parameters, transmitter
output scaling, Maintenance Set Point settings and calibration.

12
MAIN MENUS and SUB MENUS
SECr (Security) MAIN MENU
SECr is the only SUB MENU in the security MENU. When the security
SUB MENU is selected, the present security level is displayed in the
upper right hand display. To change the security level, adjust the
number displayed to the number shown in the following table for the
desired security level.
The password values shown in the table cannot be altered, so retain a copy
of these pages for future reference.
OPEr (Operation) MAIN MENU
The OPEr MENU selects the measurement type of the instrument.
The SUB MENUS are:
PrES - Pressure KFAC - K Factor XDIM - X Dimension
UEL - Velocity ArEA - Area YDIM - Y Dimension
FLO - Flow DIA - Diameter
If the instrument is set for Velocity, the OPEr MENU will have an additional KFAC
SUB MENU. If the instrument is set for Flow, the OPEr MENU will have additional
KFAC and ArEA SUB MENUS. These will be discussed under Velocity and Flow.
When scrolling through the
OPEr SUB MENUS, the measurement type the unit is
currently set for will show the units in the upper right display. The other measure-
ment types will have a blank upper right display.
Security Level
Displayed
1
2
3
4
Access
All menus access
Menu Access
SP/AL Locked
SP/AL Access
Menus Locked
All settings locked
Password
Value to Enter
10
70
90
111
Units visible, so unit
is presently set to
measure pressure
is presently set to
measure pressure
Units not visibleUnits not visible Units not visibleUnits not visible

13
PrES (Pressure) SUB MENU
For pressure measurement, the following units are available:
Table 1 Pressure Range vs. Available Units
INWC
.1000
.2500
.5000
1.000
2.500
5.000
10.00
25.00
50.00
100.0
FTWC
.2083
.4167
.8333
2.083
4.167
8.333
MMWC
2.540
6.350
12.70
25.40
63.50
127.0
254.0
635.0
1270
2540
CMWC
.2540
.6350
1.270
2.540
6.350
12.70
25.40
63.50
127.0
254.0
PSI
.1806
.3613
.9032
1.806
3.613
INHG
.1839
.3678
.7356
1.839
3.678
7.356
MMHG
.1868
.4671
.9342
1.868
4.671
9.342
18.68
46.71
93.42
186.8
MBAR
.2491
.6227
1.245
2.491
6.227
12.45
24.91
62.27
124.5
249.1
PA
24.91
62.27
124.5
249.1
622.7
1245
2491
6227
KPA
.1245
.2491
.6227
1.245
2.491
6.227
12.45
24.91
HPA
.2491
.6227
1.245
2.491
6.227
12.45
24.91
62.27
124.5
249.1
OZIN
.1445
.2890
.5780
1.445
2.890
5.780
14.45
28.90
57.80
UEL (Velocity) SUB MENU
For velocity measurement, the following units are available:
SFPM - Standard feet per minute
M/S - Meters per second
Table 2 Available Velocity Ranges
NOTE: Air velocity and flow readings are based upon standard dry air conditions with an
ambient temperature of 70°F and a barometric pressure of 29.92 INHG.
INPUT RANGE INWC
0 - 0.1
0 - 0.25
0 - 0.5
0 - 1
0 - 2.5
0 - 5
0 - 10
0 - 25
SFPM RANGE
0 - 1266
0 - 2002
0 - 2832
0 - 4004
0 - 6332
0 - 8954
0 - 12.66 x IK
0 - 20.02 x IK
M/S RANGE
0 - 6.431
0 - 10.17
0 - 14.39
0 - 20.35
0 - 32.17
0 - 45.48
0 - 64.33
0 - 101.7
INWC - Inches of water column
FTWC - Feet of water column
MMWC - Millimeters of water column
CMWC - Centimeters of water column
PSI - Pounds per square inch
INHG - Inches of mercury
MMHG - Millimeters of mercury
MBAR - Millibar
PA - Pascal
KPA - Kilopascals
HPA - Hectopascals
OZIN - Ounce inches
NOTE: OVFL (over flow) or UnFL (under flow) will appear when the ranges have been
exceeded above or below full scale by 2%.

14
FLO (Flow) SUB MENU
For flow measurements the following units are available:
SCFM - Standard cubic feet per minute
M^3H - Cubic meters per hour
FLO r (Flow Range) SUB MENU
LO - 99.99 x 1K flow range
HI - 999.9 x 1K flow range
Tables 3-6 show the flow ranges available, and the maximum duct size that can
be set for each input range.
Table 3
FLOr =LO Maximum Duct Size (English)
RANGE
IN WC
0.1
0.25
0.5
1
2.5
5
10
25
SCFM
RANGE
99.99 x 1K
99.99 x 1K
99.99 x 1K
99.99 x 1K
99.99 x 1K
99.99 x 1K
99.99 x 1K
99.99 x 1K
MAX. DUCT
SIZE, SQ. FT.
78.9
49.9
35.3
24.9
15.7
11.1
7.8
4.9
KFAC SUB MENU
KFAC K Factor - becomes accessible if the instrument is set for Velocity or Flow.
When the DH3®is used with a Pitot tube, the manufacturer may specify
a K Factor. The adjustment range is 0.01 to 2.00. The factory setting is 1.
Table 4
FLOr =HI Maximum Duct Size (English)
RANGE
IN WC
0.1
0.25
0.5
1
2.5
5
10
25
SCFM
RANGE
999.9 x 1K
999.9 x 1K
999.9 x 1K
999.9 x 1K
999.9 x 1K
999.9 x 1K
999.9 x 1K
999.9 x 1K
MAX. DUCT
SIZE, SQ. FT.
789.8
499.5
353.1
249.7
157.9
111.7
78.9
49.9
Table 5
FLOr =LO Maximum Duct Size (Metric)
RANGE
IN WC
0.1
0.25
0.5
1
2.5
5
10
25
Mˆ3/Hr
RANGE
99.99 x 1K
99.99 x 1K
99.99 x 1K
99.99 x 1K
99.99 x 1K
99.99 x 1K
99.99 x 1K
99.99 x 1K
MAX. DUCT
SIZE Mˆ2
4.32
2.73
1.93
1.37
0.86
0.61
0.43
0.27
Table 6
FLOr =HI Maximum Duct Size (Metric)
RANGE
IN WC
0.1
0.25
0.5
1
2.5
5
10
25
M3/Hr
Range
999.9 x 1K
999.9 x 1K
999.9 x 1K
999.9 x 1K
999.9 x 1K
999.9 x 1K
999.9 x 1K
999.9 x 1K
MAX. DUCT
SIZE, M2
43.19
27.31
19.3
13.64
8.63
6.10
4.31
2.73

15
ArEA , DIA , XDIM and YDIM SUB MENUS
These SUB MENUS become accessible if the instrument is set for flow. When meas-
uring flow, the area of the duct must be specified. Tables 3 and 4 show the input
range vs maximum flow and duct size. For a rectangular duct the maximum size is
specified in square feet or meters. For a circular duct the maximum size is specified
as the diameter. X, Y and circular dimensions are entered in feet with 0.01 foot res-
olution for
FLOr = LO and 0.1 foot resolution for FLOr = HI , or entered in millimeters
with 1 millimeter resolution.
ArEA - Area, select CIR for a circular duct or RECT for a rectangular
duct. If a circular duct is selected, the DIA SUB MENU will be activated. If a
rectangular duct is selected, the
XDIM and YDIM SUB MENUS will be acti-
vated.
DIA - Diameter, enter the diameter of a duct
XDIM - Enter the “X” dimension of a duct
YDIM - Enter the “Y” dimension of a duct
OUt (Output) MAIN MENU
The OUt MENU selects the output type of the instrument. The SUB
MENUS are:
CtrL - Control type ALrE - Alarm reset, manual or auto
ISP - SP1 reverse or direct acting AL.H - Alarm inhibit
AL - Alarm type ALDL - Alarm delay
Y
X

16
0
100
Process
Reverse Acting
Time
SPH
SPL
Relay Inactive
Relay Active
CtrL (Control) SUB MENU
1SP - Single set point
2SP - Two fully independent set points
SPAL - Single set point and alarm
1SP (SP1 Reverse or Direct Acting) SUB MENU
DIR - Direct. Relay turns on with increasing pressure
REV - Reverse. Relay turns on with decreasing pressure
0
100
Process
Direct Acting
Time
SPH
SPL
Relay Inactive
Relay Active

17
The following alarm function SUB MENUS are activated when CtrL is set to
SPAL :
AL (Alarm Type) SUB MENU
HI - High alarm
LO - Low alarm
HILO - For a high/low guardband type alarm
ALARM ADJUSTMENT
Alarm settings are dependent upon the selected alarm mode. The DH3®differential
pressure controller alarm may be configured as a High Alarm, Low Alarm, or
High/Low Alarm. Alarm settings are all absolute and may be set to anywhere within
the range of the instrument. The dead bands of the alarms are fixed at 1% of full
scale.
MIN. PRESSURE MAX. PRESSURE
ALHI
Relay OFF Relay ON
HIGH ALARM FUNCTION
MIN. PRESSURE MAX. PRESSURE
ALLO
Relay ON Relay OFF
LOW ALARM FUNCTION
MIN. PRESSURE MAX. PRESSURE
ALLO
Relay ON Relay OFF Relay ON
HIGH/LOW ALARM
FUNCTION
ALHI

18
AL0S (Alarm Output State) SUB MENU
CL0S - Alarm relay contacts close upon alarm condition
0PEN - Alarm relay contacts open upon alarm condition
ALrE (Alarm Reset) SUB MENU
ONOF - Automatic reset
HOLD - Manual reset. An alarm is reset by the RESET key on the front
panel, or an external reset switch.
AL.H (Low Alarm Inhibit) SUB MENU
ON - Alarm inhibit is on
OFF - Alarm inhibit is off
If AL.H is selected ON, a low alarm condition is suspended upon power
up until the process value passes through the alarm set point once.
ALDL (Alarm Delay) SUB MENU
Sets the amount of time an alarm condition must be continuously met before
the alarm condition is recognized. The alarm delay is adjustable from 0-3600
seconds.
d.S (Display) MAIN MENU
PEAK - Peak value rESO - Resolution
VALy - Valley value Pd.S - Process display
ZERO - Zero DAMP - Dampening level
PEAK (Peak) SUB MENU
The Peak feature stores the highest pressure reading the instrument has
measured since the last reset or power up. At power up
PEAK is reset
to the present pressure reading. To manually reset the PEAK value,
press the RESET key while in the PEAK SUB MENU.
VALy (Valley) SUB MENU
The valley feature stores the lowest pressure reading the instrument has
measured since the last reset or power up. At power up VALy is reset to
the present pressure reading. To manually reset the VALy value, press the
RESET key while in the VALy SUB MENU.

19
rESO (Resolution) SUB MENU
The DH 3 is capable of displaying four digits of resolution. However, at
very low pressures the instability of the pressure may cause fluctuations in
the least significant digit causing the least significant digit to be of little value.
Three digit resolution ( 3DIG ) can only be active when there is at least one digit
to the right of a decimal.
3DIG - Set display for 3 digit resolution
4DIG - Set display for 4 digit resolution
Pd.S (Process Display) SUB MENU
STD - Display reads pressure, velocity, or flow values
PCT - Display reads % of full scale value
When the display is reading percent, PCT is displayed in the upper right of
the display. The percent display is only available in pressure operation.
DAMP (Dampening) SUB MENU
Adjust from 1-16
Dampening stabilizes the display from instabilities due to things such as
vibration and excessive pressure fluctuations. The dampening setting adjusts
the amount of readings that are averaged for each display update. Adjust
the dampening value until the display reads a stable value for the application.
AdU (Advanced) MAIN MENU
POL - Process output low ZERO - Zero calibration
POH - Process output high SPAN - Span calibration
MSP1 - Maintenance set point 1
MSP2 - Maintenance set point 2
POL and POH (Process Output Low and High) SUB MENUS
This feature is used in pressure operation only.
Process output low and high are used to scale the 4-20 mA output. Set
POL to the desired display reading for 4mA output, and set POH to the
desired display reading for 20 mA output.
POH must be higher than POL .
POL may be adjusted 2% BELOW minimum scale up to POH . POH may
be adjusted from
POL to 2% ABOVE maximum scale.

MSP1 and MSP2 (Maintenance Set Point 1 & 2) SUB MENUS
Adjust for the desired maintenance set points when the unit is placed in the
maintenance mode. The deadband is fixed at 2% of full scale. To enter or
leave the maintenance mode, press and hold the for 8 seconds.
ZERO and SPAN (Calibration of Zero and Span) SUB MENUS
The lower display reads CAL in this mode.
ZERO Calibration
NOTE: For accurate calibration, DO NOT apply any pressure when
performing this function.
With the display reading ZERO , press the ENTER key. The upper display will
blink. Press ENTER again to complete the zeroing of the instrument or press
the MENU key to cancel.
SPAN Calibration
With the display set to SPAN , apply full scale pressure to the unit. Press the
ENTER key. The upper display will blink. Press ENTER again to complete the
calibration or press the MENU key to cancel.
SP/ALSP/AL
MENUMENU
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