Aalborg XFM Series User manual

Technical Data Sheet No. TD0701M Rev. D Date of Issue: November 2016
OPERATING MANUAL
XFM DIGITAL MASS
FLOW METERS

TABLE OF CONTENTS
1. UNPACKING THE XFM MASS FLOW METER.........................................
1.1 Inspect Package for External Damage.................................................
1.2 Unpack the Mass Flow Meter...............................................................
1.3 Returning Merchandise for Repair.......................................................
2. INSTALLATION........................................................................................
2.1 Primary Gas Connections.................................................................
2.2 Electrical Connections......................................................................
2.2.1 Power Supply Connections..............................................................
2.2.2 Output Signals Connections..............................................................
2.2.3 Communication Parameters and Connections...................................
3. PRINCIPLE OF OPERATION..................................................................
4. SPECIFICATIONS...................................................................................
4.1 CE Compliance.................................................................................
5. OPERATING INSTRUCTIONS..................................................................
5.1 Preparation and Warm Up..................................................................
5.2 Swamping Condition.......................................................................
5.3 XFM Parameters Settings.................................................................
5.3.1 Engineering Units Settings...............................................................
5.3.2 Gas Table Settings..............................................................................
5.3.3 Totalizer Settings.............................................................................
5.3.4 Flow Alarm Settings......................................................................
5.3.5 Relay Assignment Settings............................................................
5.3.6 K Factors Settings...........................................................................
5.3.7 Zero Calibration...............................................................................
5.3.8 Self Diagnostic Alarm.......................................................................
5.4 Analog output Signals configuration...................................................
6. MAINTENANCE.........................................................................................
6.1 Introduction......................................................................................
6.2 Flow Path Cleaning...........................................................................
6.2.1 Restrictor Flow Element (RFE)........................................................
6.2.2 XFM 17 models................................................................................
6.2.3 XFM 37/47 models..........................................................................
6.2.4 XFM 57/67/77 models.....................................................................
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7. CALIBRATION PROCEDURES.................................................................
7.1 Flow Calibration...............................................................................
7.2 Gas Calibration of XFM Mass Flow Meters........................................
7.2.1 Connections and Initial Warm Up.....................................................
7.2.2 ZERO Check/Adjustment Adjustment.................................................
7.2.3 Gas Linearization Table Adjustment.................................................
7.3 Analog output Calibration of XFM Mass Flow Meters.......................
7.3.1 Initial Setup.......................................................................................
7.3.2 Gas flow 0-5 Vdc analog output calibration....................................
7.3.3 Gas flow 4-20 mA analog output calibration...................................
8. RS-485/RS-232 SOFTWARE INTERFACE COMMANDS...........................
8.1 General............................................................................................
8.2 Commands Structure.........................................................................
8.3 ASCII Commands Set.........................................................................
9. TROUBLESHOOTING................................................................................
9.1 Common Conditions.......................................................................
9.2 Troubleshooting Guide.....................................................................
9.3 Technical Assistance.......................................................................
10. CALIBRATION CONVERSIONS FROM REFERENCE GASES....................
APPENDIX I AALBORG XFM EEPROM Variables........................................
APPENDIX II INTERNAL USER SELECTABLE GAS FACTOR TABLE
(INTERNAL "K" FACTORS)........................................................
APPENDIX III GAS FACTOR TABLE ("K" FACTORS)....................................
APPENDIX IV COMPONENT DIAGRAM......................................................
APPENDIX V DIMENSIONAL DRAWINGS.................................................
APPENDIX VI WARRANTY...........................................................................
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1. UNPACKING THE XFM MASS FLOW METER
1.1 Inspect Package for External Damage
Your XFM Mass Flow Meter was carefully packed in a sturdy cardboard carton,
with anti-static cushioning materials to withstand shipping shock. Upon receipt,
inspect the package for possible external damage. In case of external damage to
the package contact the shipping company immediately.
1.2 Unpack the Mass Flow Meter
Open the carton carefully from the top and inspect for any sign of concealed ship-
ping damage. In addition to contacting the shipping carrier please forward a copy
of any damage report to your distributor or Aalborg7directly.
When unpacking the instrument please make sure that you have all the items
indicated on the Packing List. Please report any shortages promptly.
1.3 Returning Merchandise for Repair
Please contact the customer service representative of your distributor or Aalborg7
if you purchased your Mass Flow Meter directly, and request a Return
Authorization Number (RAN). Equipment returned without an RAN will not
be accepted. Aalborg7reserves the right to charge a fee to the customer for
equipment returned under warranty claims if the instruments are tested to be free
from warrantied defects.
Shipping charges are borne by the customer. Meters returned "collect" will not be
accepted!
It is mandatory that any equipment returned for servicing be purged and neutral-
ized of any dangerous contents including but not limited to toxic, bacterially infec-
tious, corrosive or radioactive substances. No work shall be performed on a
returned product unless the customer submits a fully executed, signed SAFETY
CERTIFICATE. Please request form from the Service Manager.
2. INSTALLATION
2.1 Primary Gas Connections
Please note that the XFM Mass Flow Meter will not operate with liquids. Only
clean gases are allowed to be introduced into the instrument. If gases are con-
taminated they must be filtered to prevent the introduction of impediments into the
sensor.

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CAUTION: It is the user’s responsibility to determine if the instrument is
appropriate for their OXYGEN application and for specifying O2 cleaning
service if required. Aalborg is not liable for any damage or personal injury,
whatsoever, resulting from the use of this instrument for oxygen.
For more information, contact your distributor or Aalborg 7 .
Attitude limit of the Mass Flow Meter is ±15Ffrom calibration position (standard
calibration is in horizontal position). This means that the gas flow path of the Flow
Meter must be within this limit in order to maintain the original calibration accura-
cy. Should there be need for a different orientation of the meter, re-calibration may
be necessary. It is also preferable to install the XFM transducer in a stable envi-
ronment, free of frequent and sudden temperature changes, high moisture, and
drafts.
Prior to connecting gas lines inspect all parts of the piping system including fer-
rules and fittings for dust or other contaminant’s.
When connecting the gas system to be monitored, be sure to observe the direc-
tion of gas flow as indicated by the arrow on the front of the meter.
Insert tubing into the compression fittings until the ends of the properly sized tub-
ing home flush against the shoulders of the fittings. Compression fittings are to be
tightened to one and one quarter turns according to the manufacturer's instruc-
tions. Avoid over tightening which will seriously damage the Restrictor Flow
Elements (RFE's)!
CAUTION: For XFM 17/37/47/57/67/77 models, the maximum pressure in the
gas line should not exceed 500 PSIA (34.47 bars). Applying pressure above
500 PSIA (34.47 bars) will seriously damage the flow sensor.
XFM transducers are supplied with either standard 1/4 inch (XFM 17 and 37), 3/8
inch (XFM 47/57), ½ inch (GDFM 67), or optional 1/8 inch inlet and outlet com-
pression fittings which should NOT be removed unless the meter is being cleaned
or calibrated for a new flow range. XFM 77 transducers are supplied with ¾ inch
FNPT fittings.
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2.2 Electrical Connections
XFM is supplied with a 15 pin "D" connector. Pin diagram is presented in Figure b-1.
2.2.1 Power Supply Connections
The power supply requirements for XFM transducers are: 11 to 26 Vdc, (unipo-
lar power supply)
DC Power (+) --------------- pin 7 of the 15 pin "D" connector
DC Power (-) --------------- pin 5 of the 15 pin "D" connector
CAUTION: Do not apply power voltage above 26Vdc.
Doing so will cause XFM damage or faulty operation.
2.2.2 Output Signals Connections
CAUTION: When connecting the load to the output terminals, do not exceed
the rated values shown in the specifications. Failure to do so might cause
damage to this device. Be sure to check if the wiring and the polarity of the
power supply is correct before turning the power ON. Wiring error may cause
damage or faulty operation.
XFM series Mass Flow Meters are equipped with either calibrated 0-5 or cali-
brated 4-20 mA output signals (jumper selectable). This linear output signal rep-
resents 0-100% of the flow meter’s full scale range.
WARNING: The 4-20 mA current loop output is self-powered (non-isolated).
Do NOT connect an external voltage source to the output signals.
Flow 0-5 VDC or 4-20 mA output signal connection:
Plus (+) --------------------------- pin 2 of the 15 pin "D" connector
Minus (-)--------------------------- pin 1 of the 15 pin "D" connector
To eliminate the possibility of noise interference, use a separate cable entry for
the DC power and signal lines.
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2.2.3 Communication Parameters and Connections
The digital interface operates via RS485 (optional RS-232 or Profibus DP avail-
able) and provides access to applicable internal data including: flow, CPU tem-
perature reading, auto zero, totalizer and alarm settings, gas table, conversion
factors and engineering units selection, dynamic response compensation and lin-
earization table adjustment.
Communication Settings for RS-485/RS-232 communication interface:
Baud rate: ...................... 9600 baud
Stop bit: ...................... 1
Data bits: ...................... 8
Parity: ...................... None
Flow Control: ...................... None
RS-485 communication interface connection:
The RS485 converter/adapter must be configured for: multidrop, 2 wire, half
duplex mode. The transmitter circuit must be enabled by TD or RTS (depending
on which is available on the converter/adapter). Settings for the receiver circuit
should follow the selection made for the transmitter circuit in order to eliminate
echo.
RS-485 T(-) or R(-) ...................... pin 8 of the 15 pin "D" connector (TX-)
RS-485 T(+) or R(+) ...................... pin 15 of the 15 pin "D" connector (RX+)
RS-485 GND (if available) ...................... pin 9 of the 15 pin "D" connector (GND)
RS-232 communication interface connection:
Crossover connection has to be established:
RS-232 RX (pin 2 on the DB9 connector) ..... pin 8 of the 15 pin "D" connector (TX)
RS-232 TX (pin 3 on the DB9 connector) ..... pin 15 of the 15 pin "D" connector (RX)
RS-232 GND (pin 5 on the DB9 connector) ..... pin 9 of the 15 pin "D" connector (GND)
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Figure b-1 - XFM 15 PIN "D" CONNECTOR CONFIGURATION
IMPORTANT NOTES:
Generally, "D" Connector numbering patterns are standardized. There are, how-
ever, some connectors with nonconforming patterns and the numbering sequence
on your mating connector may or may not coincide with the numbering sequence
shown in our pin configuration table above. It is imperative that you match the
appropriate wires in accordance with the correct sequence regardless of the par-
ticular numbers displayed on the mating connector.
Make sure power is OFF when connecting or disconnecting any cables in
the system.
The (+) and (-) power inputs are each protected by a 300mA M (medium time-lag)
resettable fuse. If a shorting condition or polarity reversal occurs, the fuse will cut
power to the flow transducer circuit. Disconnect the power to the unit, remove the
faulty condition, and reconnect the power. The fuse will reset once the faulty con-
dition has been removed. DC Power cable length may not exceed 9.5 feet (3
meters). Use of the XFM flow transducer in a manner other than that specified in
this manual or in writing from Aalborg, may impair the protection provided by the
equipment.
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PIN XFM FUNCTION
1Common, Signal Ground For Pin 2
(4-20 mA return)
20-5 Vdc or 4-20mA Flow Signal Output
3Relay No. 2 - Normally Open Contact
4Relay No. 2 - Common Contact
5Common, Power Supply
(- DC power for 11 to 26 Vdc)
6Relay No. 1 - Common Contact
7Plus Power Supply
(+ DC power for 11 to 26 Vdc)
8RS485 (-) (Optional RS232 TX)
9RS232 Signal GND (RS-485 GND Optional)
10 Do not connect (Test/Maintenance terminal)
11 Relay No. 2 - Normally Closed Contact
12 Relay No. 1 - Normally Open Contact
13 Relay No. 1 - Normally Closed Contact
14 Do not connect (Test/Maintenance terminal)
15 RS485 (+) (Optional RS232 RX)
Shield Chassis Ground

3. PRINCIPLE OF OPERATION
The stream of gas entering the Mass Flow transducer is split by shunting a small
portion of the flow through a capillary stainless steel sensor tube. The remainder of
the gas flows through the primary flow conduit. The geometry of the primary con-
duit and the sensor tube are designed to ensure laminar flow in each branch.
According to principles of fluid dynamics the flow rates of a gas in the two laminar
flow conduits are proportional to one another. Therefore, the flow rates measured
in the sensor tube are directly proportional to the total flow through the transducer.
In order to sense the flow in the sensor tube, heat flux is introduced at two sec-
tions of the sensor tube by means of precision wound heater-sensor coils. Heat is
transferred through the thin wall of the sensor tube to the gas flowing inside. As
gas flow takes place heat is carried by the gas stream from the upstream coil to
the downstream coil windings. The resultant temperature dependent resistance
differential is detected by the electronic control circuit. The measured temperature
gradient at the sensor windings is linearly proportional to the instantaneous rate
of flow taking place.
An output signal is generated that is a function of the amount of heat carried by
the gases to indicate mass-molecular based flow rates.
Additionally, the XFM model Mass Flow Meter incorporates a Precision Analog
Microcontroller (ARM7TDMI®MCU) and non-volatile memory that stores all hard-
ware specific variables and up to 10 different calibration tables. The flow rate can be
displayed in 23 different volumetric or mass flow engineering units. Flow meter
parameters and functions can be programmed remotely via the RS-232/RS-485
interface or optional Profibus DP interface. XFM flow meters support various func-
tions including: programmable flow totalizer, low, high or range flow alarm, auto-
matic zero adjustment (activated via local button or communication interface), 2 pro-
grammable SPDT relays output, 0-5 Vdc / 4-20 mA analog outputs (jumper selec-
table), self diagnostic alarm, 36 internal and user defined K-factor. Optional local
2x16 LCD readout with adjustable back light provides flow rate and total volume
reading in currently selected engineering units and diagnostic events indication.
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4. SPECIFICATIONS
FLOW MEDIUM: Please note that XFM Mass Flow Meters are designed to work only with
clean gases. Never try to measure flow rates of liquids with any XFM.
CALIBRATIONS: Performed at standard conditions [14.7 psia (101.4 kPa) and 70FF
(21.1FC)] unless otherwise requested or stated.
ENVIRONMENTAL (PER IEC 664): Installation Level II; Pollution Degree II.
FLOW ACCURACY (INCLUDING LINEARITY): ±1% of FS at calibration temperature and
pressure.
REPEATABILITY: ±0.15% of full scale.
FLOW TEMPERATURE COEFFICIENT: 0.15% of full scale/ FC or better.
FLOW PRESSURE COEFFICIENT: 0.01% of full scale/psi (6.895 kPa) or better.
FLOW RESPONSE TIME: 1000ms time constant; approximately 2 seconds to
within ±2% of set flow rate for 25% to 100% of full scale flow.
MAXIMUM GAS PRESSURE: 500 psig (3447 kPa gauge).
MAXIMUM PRESSURE DROP: 0.18 PSID (at 10 L/min flow). 8 psi (at 100 L/min flow).
See Table IV for pressure drops associated with various models and flow rates.
GAS AND AMBIENT TEMPERATURE: 32 FF to 122 FF (0 FC to 50 FC). 14 FF to 122 FF
(-10 FC to 50 FC) - Dry gases only.
RELATIVE GAS HUMIDITY: Up to 70%.
LEAK INTEGRITY: 1 x 10-9 sccs He maximum to the outside environment.
ATTITUDE SENSITIVITY: Incremental deviation of up to 1% from stated accuracy, after re-
zeroing.
OUTPUT SIGNALS: Linear 0-5 Vdc (3000 ohms min load impedance);
Linear 4-20 mA (500 ohms maximum loop resistance).
Maximum noise 20mV peak to peak (for 0-5 Vdc output).
TRANSDUCER INPUT POWER: 11 to 26 Vdc, 100 mV maximum peak to peak output
noise.
Power consumption: +12Vdc (200 mA maximum);
+24Vdc (100 mA maximum);
Circuit board have built-in polarity reversal protection, 300mA resettable fuse provide
power input protection.
WETTED MATERIALS: Anodized aluminum, brass, 316 stainless steel, 416 stainless steel,
VITON7O-rings; BUNA-N7, NEOPRENE7or KALREZ7O-rings are optional.

CAUTION: Aalborg makes no expressed or implied guarantees of corrosion
resistance of mass flow meters as pertains to different flow media reacting with
components of meters. It is the customers' sole responsibility to select the
model suitable for a particular gas based on the fluid contacting (wetted)
materials offered in the different models.
INLET AND OUTLET CONNECTIONS:
Model XFM 17/37 standard 1/4” compression fittings,
Model XFM 47/57 standard 3/8” compression fittings,
Model XFM 67 standard 1/2” compression fittings,
Model XFM 77 standard 3/4” FNPT fittings,
Optional 1/8” or 3/8” compression fittings and 1/4” VCR fittings are available.
DISPLAY: Optional local 2x16 characters LCD with adjustable backlight (2 lines of text).
CALIBRATION OPTIONS: Standard is one 10 points NIST calibration. Optional, up to 9
additional calibrations may be ordered at additional charge.
4.1 CE Compliance
EMC Compliance with 89/336/EEC as amended.
Emission Standard: EN 55011:1991, Group 1, Class A,
Immunity Standard: EN 55082-1:1992.
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*Flow rates are stated for Nitrogen at STP conditions [i.e. 70 FF (21.1 FC) at 1 atm].
For other gases use the K factor as a multiplier from APPENDIX 2.
CODE scc/min [N2]CODE std liters/min [N2]
00 0 to 5 07 0 to 1
01 0 to 10 08 0 to 2
02 0 to 20 09 0 to 5
03 0 to 50 10 0 to 10
04 0 to 100
05 0 to 200
06 0 to 500
TABLE I XFM 17 LOW FLOW MASS FLOW METER*
TABLE II XFM 37 MEDIUM FLOW MASS FLOW METER*
FLOW RANGES
CODE std liters/min [N2]
30 20
31 30
32 40
33 50
TABLE III XFM XFM 47/57/67/77 HIGH FLOW MASS FLOW METERS*
CODE std liters/min [N2]
40 60
41 80
42 100
50 200
60 500
70 1000

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TABLE IV PRESSURE DROPS
TABLE V APPROXIMATE WEIGHTS
MODEL FLOW RATE
[std liters/min]
MAXIMUM PRESSURE DROP
[mm H2O] [psid] [kPa]
XFM 17 up to 10 130 0.18 1.275
XFM 37
20 TBD TBD TBD
30 TBD TBD TBD
40 TBD TBD TBD
50 TBD TBD TBD
XFM 47 60 TBD TBD TBD
100 TBD TBD TBD
XFM 57 200 TBD TBD TBD
XFM 67 500 TBD TBD TBD
XFM 77 1000 TBD TBD TBD
MODEL WEIGHT SHIPPING WEIGHT
XFM 17 transmitter 2.20 lbs. (1.00 kg) 3.70 lbs. (1.68 kg)
XFM 37/47 transmitter 2.95 lbs. (1.33 kg) 4.34 lbs. (1.97 kg)
XFM 57 transmitter TBD TBD
XFM 67 transmitter TBD TBD
XFM 77 transmitter TBD TBD

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5. OPERATING INSTRUCTIONS
5.1 Preparation and Warm Up
It is assumed that the Mass Flow Meter has been correctly installed and thor-
oughly leak tested as described in section 2. Make sure the flow source is OFF.
When applying power to a flow meter within the first two seconds, you will see on
the LCD display: the product name, the software version, and revision of the EEP-
ROM table (applicable for LCD option only).
Figure b-2: XFM first Banner Screen
Within the next two seconds, the RS-485 network address, the analog output set-
tings, and currently selected gas calibration table will be displayed (applicable for
LCD option only).
Figure b-3: XFM second Banner Screen
Note: Actual content of the LCD screen may vary depending on the
model and device configuration.
After two seconds, the LSD display switches to the main screen with the
following information:
- Mass Flow reading in current engineering units (upper line).
- Totalizer Volume reading in current volume or mass based
engineering units (lower line).
Figure b-4: XFM Main Screen
AALBORG XFM 485
S: Ver1.4 Rev.A0
Ad: 11 Out: 0-5Vdc
Gas# 1 AIR
F: 50.0 L/min
T: 75660.5 Ltr
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During initial powering of the XFM transducer, the flow output signal will be indi-
cating a higher than usual output. This is an indication that the XFM transducer
has not yet attained its minimum operating temperature. This condition will auto-
matically cancel within a few minutes and the transducer should eventually indi-
cate zero.
For the XFM transducer with LCD option: If the LCD diagnostic is activated, the
second line of the LCD will display the time remaining until the end of the warm
up period (Minutes:Seconds format) and will alternatively switch to Totalizer read-
ing indication every 2 seconds.
Figure b-5: XFM Main Screen during Sensor Warm up period.
5.2 Swamping Condition
If a flow of more than 10% above the maximum flow rate of the Mass Flow Meter
is taking place, a condition known as "swamping" may occur. Readings of a
"swamped" meter cannot be assumed to be either accurate or linear. Flow must
be restored to below 110% of maximum meter range. Once flow rates are lowered
to within calibrated range, the swamping condition will end. Operation of the meter
above 110% of maximum calibrated flow may increase recovery time.
Note: Allow the Digital Mass Flow Meter to warm-up for a MINIMUM
of 6 minutes.
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Note: During the first 6 minutes of the initial powering of the XFM
transducer, the status LED will emit CONSTANT AMBER light.
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Note: After 6 minutes of the initial powering of the XFM transducer,
the status LED will emit a constant GREEN light (normal operation,
ready to measure). For XFM with LCD option, the screen will reflect
flow and totalizer reading. (see Figure b-4).
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F: 50.0 L/min
** WarmUp 2:39 **

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5.3 XFM Parameters Settings
5.3.1 Engineering Units Settings
The XFM Mass Flow Meter is capable of displaying flow rate with 23 different
Engineering Units. Digital interface commands (see paragraph 8.3 ASCII
Command Set “XFM SOFTWARE INTERFACE COMMANDS”) are provided to:
- get currently active Engineering Units
- set desired Engineering Units.
The following Engineering Units are available:
TABLE VI UNITS OF MEASUREMENT
NUMBER INDEX
FLOW RATE
ENGINEERING
UNITS
TOTALIZER
ENGINEERING
UNITS
DESCRIPTION
1 0 % %s Percent of full scale
2 1 mL/sec mL Milliliter per second
3 2 mL/min mL Milliliter per minute
4 3 mL/hr mL Milliliter per hour
5 4 L/sec Ltr Liter per second
6 5 L/ min Ltr Liter per minute
7 6 L/hr Ltr Liter per hour
87m3/sec m3Cubic meter per second
98
m3/ min m3Cubic meter per minute
10 9 m3/hr m3Cubic meter per hour
11 10 f3/sec f 3Cubic feet per second
12 11 f3/min f 3Cubic feet per minute
13 12 f3/hr f 3Cubic feet per hour
14 13 g/sec g Grams per second
15 14 g/min g Grams per minute
16 15 g/hr g Grams per hour
17 16 kg/sec kg Kilograms per second
18 17 kg/min kg Kilograms per minute
19 18 kg/hr kg Kilograms per hour
20 19 Lb/sec Lb Pounds per second
21 20 Lb/min Lb Pounds per minute
22 21 Lb/hr Lb Pounds per hour
23 22 User UD User defined

5.3.2 Gas Table Settings.
The XFM Mass Flow Meter is capable of storing calibration data for up to 10 dif-
ferent gases. Digital interface commands are provided to:
- get currently active Gas Table number and Gas name
- set desired Gas Table.
5.3.3 Totalizer Settings.
The total volume of the gas is calculated by integrating the actual gas flow rate
with respect to the time. Digital interface commands are provided to:
- reset the totalizer to ZERO
- start the totalizer at a preset flow
- assign action at a preset total volume
- start/stop (enable/disable) totalizing the flow
- read totalizer via digital interface
The Totalizer has several attributes which may be configured by the user.
These attributes control the conditions which cause the Totalizer to start integrat-
ing the gas flow and also to specify actions to be taken when the Total Volume is
outside the specified limit.
Totalizer action conditions become true when the totalizer reading and preset
"Stop at Total" volumes are equal.
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Note: Once Flow Unit of Measure is changed, the Totalizer’s
Volume/Mass based Unit of Measure will be changed automatically.
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Note: By default the XFM is shipped with at least one valid calibration
table (unless optional additional calibrations were ordered). If instead
of the valid Gas name (for example NITROGEN), the LCD screen or
digital interface displays Gas designator as “Uncalibrated”, then the
user has chosen the Gas Table which was not calibrated. Using an
“Uncalibrated” Gas Table will result in erroneous reading.
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Note: Before enabling the Totalizer, ensure that all totalizer settings
are configured properly. Totalizer Start values have to be entered in
%F.S. engineering unit. The Totalizer will not totalize until the flow rate
becomes equal to or more than the Totalizer Start value. Totalizer Stop
values must be entered in currently active volume / mass based
engineering units. If the Totalizer Stop at preset total volume feature is
not required, then set Totalizer Stop value to zero.
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Mode Enable
/Disable - Allows the user to Enable/Disable Flow Alarm.
Low Alarm - The value of the monitored Flow in % F.S. below
which is considered an alarm condition.
Note: The value of the Low alarm must be less than the
value of the High Alarm.
High Alarm- The value of the monitored Flow in % F.S. above
which is considered an alarm condition.
Note: The value of the High alarm must be more than the
value of the Low Alarm.
Action Delay- The time in seconds that the Flow rate value must remain
above the high limit or below the low limit before an alarm
condition is indicated. Valid settings are in the range of 0
to 3600 seconds.
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Local maintenance push button is available for manual Totalizer reset on the field.
The maintenance push button is located on the right side of the flow meter inside
the maintenance window above the 15 pin D-connector (see Figure c-1 “XFM
configuration jumpers”).
5.3.4 Flow Alarm Settings.
XFM provides the user with a flexible alarm/warning system that monitors the Gas
Flow for conditions that fall outside configurable limits as well as visual feedback
for the user via the status LED and LCD (only for devices with LCD option) or via
a Relay contact closure.
The flow alarm has several attributes which may be configured by the user via a
digital interface. These attributes control the conditions which cause the alarm to
occur and to specify actions to be taken when the flow rate is outside the speci-
fied conditions.
Note: In order to locally Reset Totalizer, the reset push button must be
pressed during power up sequence. The following sequence is
recommended:
1. Disconnect XFM from the power.
2. Press maintenance push button (do not release).
3. Apply power to the XFM while holding down the maintenance
push button.
4. Release maintenance push button after 6 seconds. For XFM
with optional LCD, when XFM Main Screen appears
(see Figure b-4).
,
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The current Flow Alarm settings and status are available via digital interface (see
paragraph 8.3 ASCII Command Set “XFM SOFTWARE INTERFACE COM-
MANDS”).
5.3.5 Relay Assignment Settings
Two sets of dry contact relay outputs are provided to actuate user supplied equip-
ment. These are programmable via digital interface such that the relays can be
made to switch when a specified event occurs (e.g. when a low or high flow alarm
limit is exceeded or when the totalizer reaches a specified value).
THE USER CAN CONFIGURE EACH RELAY ACTION FROM 6 DIFFERENT OPTIONS:
No Action : (N) No assignment (relay is not assigned to any events and not energized).
Totalizer > Limit : (T) Totalizer reached preset limit volume.
High Flow Alarm : (H) High Flow Alarm condition.
Low Flow Alarm : (L) Low Flow Alarm condition.
Range between H&L : (R) Range between High and Low Flow Alarm condition.
Manual Enabled : (M) Activated regardless of the Alarm and Totalizer conditions.
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Latch Mode- Controls Latch feature when Relays are assigned to
Alarm event. Following settings are available:
0 - Latch feature is disabled for both relays
1 - Latch feature is enabled for Relay#1 and disabled for Relay#2
2 - Latch feature is enabled for Relay#2 and disabled for Relay#1
3 - Latch feature is enabled for both relays.
Note: If the alarm condition is detected, and the Relay is assigned to
Alarm event, the corresponding Relay will be energized.
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Note: By default, flow alarm is non-latching. That means the alarm is
indicated only while the monitored value exceeds the specified
conditions. If Relay is assigned to the Alarm event, in some cases, the
Alarm Latch feature may be desirable.
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5.3.6 K Factors Settings
Conversion factors relative to Nitrogen for up to 36 gases are stored in the XFM
(see APPENDIX II). In addition, provision is made for a user-defined conversion
factor. Conversion factors may be applied to any of the ten gas calibrations via
digital interface commands.
The available K Factor settings are:
• Disabled (K = 1).
• Internal Index The index [0-35] from internal K factor table
(see APPENDIX II).
• User Defined User defined conversion factor.
5.3.7 Zero Calibration
The XFM includes an auto zero function that, when activated, automatically
adjusts the mass flow sensor to read zero. The initial zero adjustment for your
XFM was performed at the factory. It is not required to perform zero calibration
unless the device has zero reading offset with no flow conditions.
Shut off the flow of gas into the Digital Mass Flow Meter. To ensure that no seep-
age or leak occurs into the meter, it is good practice to temporarily disconnect the
gas source. The Auto Zero may be initiated via digital communication interface or
locally by pressing the maintenance push button, which is located on the right side
of the flow meter inside the maintenance window above the 15 pin D-connector
(see Figure c-1 “XFM configuration jumpers”).
To start Auto Zero locally, press the maintenance push button. The status LED will
flash not periodically with the RED light. On the XFM with optional LCD, the fol-
lowing screen will appear:
Note: The conversion factors will not be applied for % F.S.
engineering unit.
,
Note: Before performing Zero Calibration, make sure the device is
powered up for at least 15 minutes and absolutely no flow condition is
established.
,
Note: The same maintenance push button is used for Auto Zero
initiation and Totalizer reset. The internal diagnostic algorithm will
prevent initiating Auto Zero function via the maintenance push button
before the 6 minutes sensor warm up period has elapsed.
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