Aalborg XFM Digital User Manual

Technical Data Sheet No. TD0701M Rev. C Date of Issue: September 2009

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.....................................................................

1
1
1
1

1
1
3
3
3
4

6

7
8

11
11
12
13
13
14
14
15
16
17
17
19
19

20
20
21
21
21
21
22

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...........................................................................

22
22
23
23
24
24
26
27
27
28

28
28
28
30

36
36
37
39

39

40

43

44

48

50

53

1

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 ship­ping damage. In addition to contacting the shipping carrier please forward a copy
of any damage report to your distributor or Aalborg7 directly.

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. Aalborg7 reserves 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 neutral­ized of any dangerous contents including but not limited to toxic, bacterially infec­tious, 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 con­taminated they must be filtered to prevent the introduction of impediments into the
sensor.

2

CAUTION: XFM TRANSDUCERS SHOULD NOT BE USED FOR MONITORING
OXYGEN GAS UNLESS SPECIFICALLY CLEANED AND PREPARED FOR SUCH
APPLICATION.

For more information, contact your distributor or Aalborg7.

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 accura­cy. 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 envi­ronment, free of frequent and sudden temperature changes, high moisture, and
drafts.

Prior to connecting gas lines inspect all parts of the piping system including fer­rules and fittings for dust or other contaminant’s.

When connecting the gas system to be monitored, be sure to observe the direc­tion 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 tub­ing 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 instruc­tions. 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 com­pression 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.





3

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, (unipo­lar 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 cali­brated 4-20 mA output signals (jumper selectable). This linear output signal rep­resents 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.







2.2.3 Communication Parameters and Connections

The digital interface operates via RS485 (optional RS-232 or Profibus DP avail­able) and provides access to applicable internal data including: flow, CPU tem­perature reading, auto zero, totalizer and alarm settings, gas table, conversion
factors and engineering units selection, dynamic response compensation and lin­earization 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)

4

5

Figure b-1 - XFM 15 PIN "D" CONNECTOR CONFIGURATION

IMPORTANT NOTES:

Generally, "D" Connector numbering patterns are standardized. There are, how­ever, 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 par­ticular 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 con­dition 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.





PIN XFM FUNCTION

1 Common, Signal Ground For Pin 2

(4-20 mA return)

2 0-5 Vdc or 4-20mA Flow Signal Output
3 Relay No. 2 - Normally Open Contact
4 Relay No. 2 - Common Contact
5 Common, Power Supply

(- DC power for 11 to 26 Vdc)

6 Relay No. 1 - Common Contact
7 Plus Power Supply

(+ DC power for 11 to 26 Vdc)

8 RS485 (-) (Optional RS232 TX)
9 RS232 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 con­duit 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 sec­tions 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 hard­ware 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 func­tions including: programmable flow totalizer, low, high or range flow alarm, auto­matic zero adjustment (activated via local button or communication interface), 2 pro­grammable SPDT relays output, 0-5 Vdc / 4-20 mA analog outputs (jumper selec­table), 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.

6

7

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 70

F

F

(21.1

F

C)] 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/

F

C 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

F

F to 122 FF (0 FC to 50 FC). 14 FF to 122 FF

(-10

F

C 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 re­zeroing.

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,
VITON7 O-rings; BUNA-N7, NEOPRENE7 or KALREZ7 O-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.

8



9

*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

10

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

11

5. OPERATING INSTRUCTIONS

5.1 Preparation and Warm Up

It is assumed that the Mass Flow Meter has been correctly installed and thor­oughly 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 EEP­ROM 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 set­tings, 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



12

During initial powering of the XFM transducer, the flow output signal will be indi­cating a higher than usual output. This is an indication that the XFM transducer
has not yet attained its minimum operating temperature. This condition will auto­matically cancel within a few minutes and the transducer should eventually indi­cate 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 read­ing 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.



Note: During the first 6 minutes of the initial powering of the XFM
transducer, the status LED will emit CONSTANT UMBER light.



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).



F: 50.0 L/min

** WarmUp 2:39 **

13

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

87

m

3

/sec m

3

Cubic meter per second

98

m

3

/ min m

3

Cubic meter per minute

10 9

m

3

/hr m

3

Cubic meter per hour

11 10

f

3

/sec f

3

Cubic feet per second

12 11

f

3

/min f

3

Cubic feet per minute

13 12

f

3

/hr f

3

Cubic 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 dif­ferent 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 integrat­ing 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.

14

Note: Once Flow Unit of Measure is changed, the Totalizer’s
Volume/Mass based Unit of Measure will be changed automatically.



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.



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.



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.

15

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 speci­fied 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).







The current Flow Alarm settings and status are available via digital interface (see
paragraph 8.3 ASCII Command Set “XFM SOFTWARE INTERFACE COM­MANDS”).

5.3.5 Relay Assignment Settings

Two sets of dry contact relay outputs are provided to actuate user supplied equip­ment. 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.

16

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.



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.



17

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 seep­age 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 fol­lowing 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.



18

Figure b-6: XFM Screen in the beginning of Auto Zero procedure.

The Auto Zero procedure normally takes 1 - 2 minutes during which time the DP
Zero counts and the Sensor reading changes approximately every 3 to 6 seconds.

Figure b-7: XFM during the Auto Zero procedure.

The nominal value for a fully balanced sensor is 120 Counts. If the XFM’s digital
signal processor was able to adjust the Sensor reading within 120 ± 10 counts,
then Auto Zero is considered successful. The status LED will return to a constant
GREEN light and the screen below will appear:

Figure b-7: XFM during the Auto Zero procedure.

If the device was unable to adjust the Sensor reading to within 120 ± 10 counts,
then Auto Zero is considered as unsuccessful. The constant RED light will appear
on the status LED. The user will be prompted with the “AutoZero ERROR!” screen.

AUTOZERO IS ON!

AUTOZERO IS ON!

S: 405 DP: 512

AutoZero is Done

S: 122 DP: 544

Note: The actual value of the Sensor and DP counts will vary for each
XFM.



Note: For XFM with RS-232 option all Auto Zero status info available
via digital communication interface.



19

5.3.8 Self Diagnostic Alarm

XFM series Mass Flow Meters are equipped with a self-diagnostic alarm which
is available via multicolor LED, digital interface and on screen indication (for
devices with optional LCD). The following diagnostic events are supported:

5.4 Analog Output Signals configuration

XFM series Mass Flow Meters are equipped with calibrated 0-5 Vdc and 4-20 mA
output signals. The set of the jumpers (J7A, J7B, J7C) located on the right side of
the flow meter, inside of the maintenance window above the 15 pin D-connector
(see Figure c-1 “XFM configuration jumpers” are used to switch between 0-5 Vdc
or 4-20 mA output signals (see Table VI).

NUMBER

DIAGNOSTIC ALARM

DESCRIPTION

LED COLOR

AND PATTERN

PRIORITY

LEVEL

1

Auto Zero procedure is running Not periodically flashing RED 0

2

FATAL ERROR (reset or
maintenance service is required for
return in to the normal operation)

Constant RED 1

3

CPU Temperature too high
(Electronics Overheating)

Flashing RED/UMBER 2

4

Sensor in the warm up stage
(first 6 minutes after power up
sequence, normal operation, no
critical diagnostic events present)

Constant UMBER 3

5

Flow Sensor Temperature too low Flashing UMBER/OFF 4

6

Flow Sensor Temperature too high Flashing RED/OFF 5

7

Totalizer Reading hit preset limit Flashing GREEN/UMBER 6

8

Low flow Alarm conditions Flashing GREEN/OFF 7

9

High flow Alarm conditions Flashing GREEN/RED 8

10

Normal operation, no diagnostic
events

Constant GREEN 9

Note: Priority Level is highest (most important). When two or more
diagnostic events are present at the same time, the event with the
highest priority level will be indicated on the status LED and displayed
on the LCD (if equipped). All diagnostic events may be accessed
simultaneously via digital communication interface (see paragraph 8.3
“ASCII Command Set”).



20

Analog output signals of 0-5 Vdc and 4-20 mA are attained at the appropriate pins
of the 15-pin "D" connector (see Figure b-1) on the side of the XFM transducer.

Tabl e VI Analog Output Jumper Configuration

See APPENDIX IV for actual jumpers layout on the PCB.

6. MAINTENANCE

6.1 Introduction

It is important that the Mass Flow Meter is only used with clean, filtered gases.
Liquids may not be metered. Since the RTD sensor consists, in part, of a small
capillary stainless steel tube, it is prone to occlusion due to impediments or gas
crystallization. Other flow passages are also easily obstructed.

Therefore, great care must be exercised to avoid the introduction of any potential
flow impediment. To protect the instrument, a 50 micron (XFM 17) or 60 micron
(XFM 37/47/57/67/77) filter is built into the inlet of the flow transducer. The filter
screen and the flow paths may require occasional cleaning as described below.
There is no other recommended maintenance required. It is good practice, how­ever, to keep the meter away from vibration, hot or corrosive environments and
excessive RF or magnetic interference.

If periodic calibrations are required, they should be performed by qualified per­sonnel and calibrating instruments, as described in section 7. It is recommended
that units are returned to Aalborg® for repair service and calibration.

ANALOG SIGNAL

OUTPUT

0-5 Vdc 4-20 mA

Flow Rate Output

Jumper Header J7

J7.A
J7.B
J7.C

5-9
6-10
7-11

J7.A
J7.B
J7.C

1-5
2-6
3-7

Note: Digital output (communication) is simultaneously available with
analog output.



CAUTION: TO PROTECT SERVICING PERSONNEL IT IS
MANDATORY THAT ANY INSTRUMENT BEING SERVICED IS
COMPLETELY PURGED AND NEUTRALIZED OF TOXIC,
BACTERIOLOGICALLY INFECTED, CORROSIVE OR RADIOACTIVE
CONTENTS.



21

6.2 Flow Path Cleaning

Before attempting any disassembly of the unit for cleaning, try inspecting the flow
paths by looking into the inlet and outlet ends of the meter for any debris that may
be clogging the flow through the meter. Remove debris as necessary. If the flow
path is clogged, proceed with steps below.

Do not attempt to disassemble the sensor. If blockage of the sensor tube is not alle­viated by flushing through with cleaning fluids, please return meter for servicing.

6.2.1 Restrictor Flow Element (RFE)

The Restrictor Flow Element (RFE) is a precision flow divider inside the trans­ducer which splits the inlet gas flow by a preset amount to the sensor and main
flow paths. The particular RFE used in a given Mass Flow Meter depends on the
gas and flow range of the instrument.

6.2.2 XFM 17 Models

Unscrew the inlet compression fitting of meter. Note that the Restrictor Flow
Element (RFE) is connected to the inlet fitting. Carefully disassemble the RFE
from the inlet connection. The 50 micron filter screen will now become visible.
Push the screen out through the inlet fitting. Clean or replace each of the removed
parts as necessary. If alcohol is used for cleaning, allow time for drying.

Inspect the flow path inside the transducer for any visible signs of contaminant. If
necessary, flush the flow path through with alcohol. Thoroughly dry the flow paths
by flowing clean dry gas through.

Carefully re-install the RFE and inlet fitting avoiding any twisting and deforming to
the RFE. Be sure that no dust has collected on the O-ring seal.

6.2.3 XFM 37/47 Models

Unscrew the four socket head cap screws (two 10-24 and two 6-32) at the inlet
side of the meter. This will release the short square block containing the inlet com­pression fitting.

CAUTION: DISASSEMBLY MAY COMPROMISE CURRENT CALIBRATION.



NOTE: OVER TIGHTENING WILL DEFORM AND RENDER THE RFE
DEFECTIVE. IT IS ADVISABLE THAT AT LEAST ONE CALIBRATION
POINT BE CHECKED AFTER RE-INSTALLING THE INLET FITTING.
SEE SECTION (7.2.3).



22

The 60 micron filter screen will now become visible. Remove the screen. DO NOT
remove the RFE inside the flow transducer. Clean or replace each of the removed
parts as necessary. If alcohol is used for cleaning, allow time for drying. Inspect
the flow path inside the transducer for any visible signs of contaminants.

If necessary, flush the flow path with alcohol. Thoroughly dry the flow paths by
flowing clean dry gas through. Re-install the inlet parts and filter screen. Be sure
that no dust has collected on the O-ring seal.

It is advisable that at least one calibration point be checked after re-installing the
inlet fitting (see section 7).

6.2.4 XFM 57/67/77 Models

It is not recommended to open high flow models. However, if a customer decides
to clean the RFE, the procedure below is suggested:

Unscrew the four socket head cap screws (10-24) at the inlet side of the meter.
This will release the short square block containing the inlet compression fit­ting.(3/4" NPT for XFM 77)

Remove the block and connected screens. Clean each of the removed parts as
necessary. If alcohol is used for cleaning, allow time for drying. Inspect the flow
path inside the transducer for any visible signs of contaminants. If necessary, flush
the flow path with alcohol. Thoroughly dry the flow paths by flowing clean dry gas
through.

Re-install the inlet parts. Be sure that no dust has collected on the O-ring seal. It
is advisable that at least one calibration point be checked after re-installing the
inlet fitting (see section 7).

7. CALIBRATION PROCEDURES

7.1 Flow Calibration

Aalborg® Instruments' Flow Calibration Laboratory offers professional calibration
support for Mass Flow Meters using precision calibrators under strictly controlled
conditions. NIST traceable calibrations are available. Calibrations can also be per­formed at customers' site using available standards.

Factory calibrations are performed using NIST traceable precision volumetric cal­ibrators incorporating liquid sealed frictionless actuators.

NOTE: REMOVAL OF THE FACTORY INSTALLED CALIBRATION
SEALS AND/OR ANY ADJUSTMENTS MADE TO THE METER, AS
DESCRIBED IN THIS SECTION, WILL VOID ANY CALIBRATION
WARRANTY APPLICABLE.



23

Generally, calibrations are performed using dry nitrogen gas. The calibration can
then be corrected to the appropriate gas desired based on relative correction [K]
factors shown in the gas factor table (see APPENDIX III). A reference gas, other
than nitrogen, may be used to better approximate the flow characteristics of cer­tain gases. This practice is recommended when a reference gas is found with ther­modynamic properties similar to the actual gas under consideration. The appro­priate relative correction factor should be recalculated (see section 9).

It is standard practice to calibrate Mass Flow Meters with dry nitrogen gas at

70.0˚F (21.1 ˚C), 20 psia (137.9 kPa absolute) inlet pressure and 0 psig outlet
pressure. It is best to calibrate XFM transducers to actual operating conditions.
Specific gas calibrations of non-toxic and non-corrosive gases are available for
specific conditions. Please contact your distributor or Aalborg® for a price quota­tion.

It is recommended that a flow calibrator be used which has at least four times bet­ter collective accuracy than that of the Mass Flow Meter to be calibrated.
Equipment required for calibration includes: a flow calibration standard, PC with
available RS-485/RS-232 communication interface, a certified high sensitivity
multi meter (for analog output calibration only), an insulated (plastic) screwdriver,
a flow regulator (for example - metering needle valve) installed upstream from the
Mass Flow Meter, and a pressure regulated source of dry filtered nitrogen gas (or
other suitable reference gas). Using Aalborg® supplied calibration and mainte­nance software to simplify the calibration process is recommended.

Gas and ambient temperature, as well as inlet and outlet pressure conditions,
should be set up in accordance with actual operating conditions.

7.2 Gas Flow Calibration of XFM Mass Flow Meters

XFM Mass Flow Meters may be field recalibrated/checked for the same range
they were originally factory calibrated for. When linearity adjustment is needed or
flow range changes are being made, proceed to step 7.2.3. Flow range changes
may require a different Restrictor Flow Element (RFE). Consult your distributor or
Aalborg® for more information.

7.2.1 Connections and Initial Warm Up

Power up the Mass Flow Meter for at least 15 minutes prior to commencing the
calibration procedure. Establish digital RS-485/RS-232 communication between
PC (communication terminal) and the XFM. Start Aalborg® supplied calibration
and maintenance software on the PC.

All adjustments in this section are made from the outside of the meter
via digital communication interface between a PC (terminal) and XFM.
There is no need to disassemble any part of the instrument or perform
internal PCB component (potentiometers) adjustment.



24

7.2.2 ZERO Check/Adjustment

Using Aalborg® supplied calibration and maintenance software open Back Door
access:

Query/BackDoor/Open

When software prompts with Warning, click the [YES] button. This will open the
access to the rest of the Query menu.
Start Sensor Compensated Average reading:

Query/Read/ SensorCompAverage

This will display Device Sensor Average ADC counts.

With no flow conditions, the sensor Average reading must be in the range 120±
10 counts. If it is not, perform Auto Zero procedure (see section 5.3.10 “Zero
Calibration”).

7.2.3 Gas Linearization Table Adjustment

Gas flow calibration parameters are separately stored in the Gas Dependent por­tion of the EEPROM memory for each of 10 calibration tables. See APPENDIX I
for complete list of gas dependent variables.

The XFM gas flow calibration involves building a table of the actual flow values
(indexes 114, 116, 118, 120, 122, 124, 126, 128, 130, 132, 134) and correspon­ding sensor readings (indexes 113, 115, 117, 118, 119, 121, 123, 125, 127, 129,
131, 133).

Actual flow values are entered in normalized fraction format: 100.000 % F.S. cor­responds to 1.000000 flow value and 0.000 % F.S. corresponds to 0.000000 flow
value. The valid range for flow values is from 0.000000 to 1.000000 (note: XFM
will accept up to 6 digits after decimal point).

Note: Your XFM Digital Mass Flow Meter was calibrated at the factory
for the specified gas and full scale flow range (see device’s front label).
There is no need to adjust the gas linearization table unless linearity
adjustment is needed, flow range has to be changed, or new additional
calibration is required. Any alteration of the gas linearization table will
VOID calibration warranty supplied with instrument.



Note: Make sure the correct gas number and name selected are
current. All adjustments made to the gas linearization table will be
applied to the currently selected gas. Use Gas Select command via
digital communication interface (see paragraph 8.3 ASCII Command
Set “XFM SOFTWARE INTERFACE COMMANDS”) or Aalborg®
supplied calibration and maintenance software to verify current gas
table or select a new gas table.



25

Sensor readings are entered in counts of 12 bits ADC output and should always
be in the range of 0 to 4095. There are 11 elements in the table so the data should
be obtained at an increment of 10.0 % of full scale (0.0, 10.0, 20.0, 30.0, 40.0,

50.0, 60.0, 70.0, 80.0, 90.0 and 100.0 % F.S.).

If a new gas table is going to be created, it is recommended to start calibration
from 100% full scale. If only linearity adjustment is required, calibration can be
started in any intermediate portion of the gas table.

Using the flow regulator, adjust the flow rate to 100% of full scale flow. Check the
flow rate indicated against the flow calibrator. Observe the flow reading on the
XFM. If the difference between calibrator and XFM flow reading is more than 0.5%
F.S., make a correction in the sensor reading in the corresponding position of the
linearization table (see Index 133).

If the XFM flow reading is more than the calibrator reading, the number of counts
in the index 133 must be decreased. If the XFM flow reading is less than the cal­ibrator reading, the number of counts in the index 133 must be increased. Once
Index 133 is adjusted with a new value, check the XFM flow rate against the cal­ibrator and, if required, perform additional adjustments for Index 133.

If a simple communication terminal is used for communication with the XFM, then
“MW” (Memory Write) command from the software interface commands set may
be used to adjust sensor value in the linearization table (see section 8.3 for com­plete software interface commands list).

Memory Read “MR” command can be used to read the current value of the index.
Assuming the XFM is configured with RS-485 interface and has address “11”, the
following example will first read the existing value of Index 133 and then write a
new adjusted value:

!11,MR,133[CR] - reads EEPROM address 133

!11,MW,133,3450[CR] - writes new sensor value (3450 counts) in to the index 133

Once 100% F.S. calibration is completed, the user can proceed with calibration for
another 9 points of the linearization table by using the same approach.

Note: It is recommended to use Aalborg® supplied calibration and
maintenance software for gas table calibration. This software includes
an automated calibration procedure which may radically simplify
reading and writing for the EEPROM linearization table.



Note: Do not alter memory index 113 (must be 120 counts) and 114
(must be 0.0). These numbers represent zero flow calibration points
and should not be changed.



26

7.3 Analog output Calibration of XFM Mass Flow Meters

XFM series Mass Flow Meters are equipped with cali­brated 0-5 Vdc and 4-20 mA output signals. The set of
the jumpers (J7A, J7B, J7C) on the printed circuit board
is used to switch between 0-5 Vdc and 4-20 mA output
signals (see Figure c-1 “XFM configuration jumpers).

Figure c-1 XFM Analog Output Configuration Jumpers

The XFM analog output calibration involves calculation
and storing of the offset and span variables in the EEP­ROM for each available output. The 0-5 Vdc output has
only scale variable and 20 mA output has offset and
scale variables. The following is a list of the Gas inde­pendent variables used for analog output computation:

Index Name Description

25 AoutScaleV - DAC 0-5 Vdc Analog Output Scale
27 AoutScale_mA - DAC 4-20mA Analog Output Scale
28 AoutOffset_mA - DAC 4-20mA Analog Output Offset

Note: The analog output available on the XFM Digital Mass Flow Meter
was calibrated at the factory for the specified gas and full scale flow
range (see the device’s front label). There is no need to perform analog
output calibration unless the EEPROM IC was replaced or offset/span
adjustment is needed. Any alteration of the analog output scaling
variables in the Gas independent table will VOID calibration warranty
supplied with instrument.



FUNCTION J7A

J7B J7C

JCD

ANALOG 0-5 VDC 5-9 6-10 7-11

OUTPUT 4-20 mA 1-5 2-6 3-7

RS485
TERMINAL
RESISTOR

OFF

8-12

ON 4-8

Note: It is recommended to use the Aalborg® supplied calibration and
maintenance software for analog output calibration. This software
includes an automated calibration procedure which may radically
simplify calculation of the offsets and spans variables and, the reading
and writing for the EEPROM table.



AutoZero/Reset
push button.

12
11
10

9

8

4

7

3
2

6
5

1

J7 Jumpers

CD
B

A

27

7.3.1 Initial Setup

Power up the Mass Flow Meter for at least 15 minutes prior to commencing the
calibration procedure. Make sure absolutely no flow takes place through the
meter. Establish digital RS-485/RS-232 communication between PC (communi­cation terminal) and XFM. The commands provided below assume that calibra­tion will be performed manually (w/o Aalborg® supplied calibration and mainte­nance software) and the device has RS-485 address 11. If Aalborg® supplied cal­ibration and maintenance software is used, skip the next section and follow the
software prompts.

Enter Backdoor mode by typing: !11,MW,1000,1[CR]
Unit will respond with: !11,BackDoorEnabled: Y
Disable DAC update by typing: !11,WRITE,4,D[CR]
Unit will respond with: !11,DisableUpdate: D

7.3.2 Gas flow 0-5 Vdc analog output calibration

1. Install jumpers J7A, J7B and J7C on the PC board for 0-5 Vdc output (see Table VI).

2. Connect a certified high sensitivity multi meter set for the voltage measurement to the
pins 2 (+) and 1 (-) of the 15 pins D connector.

3. Write 4000 counts to the DAC channel 1: !11,WRITE,1,4000[CR]

4. Read voltage with the meter and calculate:

5. Save FlowOutScaleV in to the EEPROM: !11,MW,25,X[CR]

Where: X – the calculated AoutScaleV value.

7.3.3 Gas flow 4-20 mA analog output calibration

1. Install jumpers J7A, J7B and J7C on the PC board for 4-20 mA output (see Table VI).

2. Connect a certified high sensitivity multi meter set for the current measurement to
pins 2 (+) and 1 (-) of the 15 pins D connector.

3. Write 4000 counts to the DAC channel 1: !11,WRITE,1,4000[CR]

4. Read current with the meter and calculate:

5. Write zero counts to the DAC channel 1: !11,WRITE,1,0CR]

6. Read offset current with the meter and calculate:

28

7. Save AoutScale_mA in to the EEPROM: !11,MW,27,Y[CR]
Save AoutOffset_mA in to the EEPROM: !11,MW,28,Z[CR]

Where: Y – the calculated AoutScale_mA value.

Z – the calculated AoutOffset_mA value.

Enable DAC update by typing: !11,WRITE,4,N[CR]
Unit will respond with: !11,DisableUpdate: N

Close BackDoor access by typing: !11,MW,1000,0[CR]
Unit will respond with: !11,BackDoorEnabled: N

8. RS-485/RS-232 SOFTWARE INTERFACE COMMANDS

8.1 General

The standard XFM comes with an RS-485 interface. For the optional RS-232
interface, the start character (!) and two hexadecimal characters for the address
must be omitted. The protocol described below allows for communications with
the unit using either a custom software program or a “dumb terminal.” All values
are sent as printable ASCII characters. For RS-485 interface, the start character
is always (!). The command string is terminated with a carriage return (line feeds
are automatically stripped out by the XFM). See section 2.2.3 for information
regarding communication parameters and cable connections.

8.2 Commands Structure

The structure of the command string:

!<Addr>,<Cmd>,Arg1,Arg2,Arg3,Arg4<CR>

Where:

! Start character **
Addr RS485 device address in the ASCII representation of hexadecimal

(00 through FF are valid).**
Cmd The one or two character command from the table below.
Arg1 to Arg4 The command arguments from the table below.

Multiple arguments are comma delimited.
CR Carriage Return character.

Note: When done with the analog output calibration make sure the
DAC update is enabled and the BackDoor is closed
(see command below).



Note: Default address for all units is 11. Do not submit start
character and two character hexadecimal device address for
RS-232 option.



29

Several examples of commands follow. All assume that the XFM has been con­figured for address 18 (12 hex) on the RS485 bus:

1. To get current calibration tables: !12,G<CR>
The XFM will reply: !12,G 0 AIR<CR> >
(Assuming Current Gas table is #0, calibrated for AIR )

2. To get current Alarm status: !12,A,R<CR>
The XFM will reply: !12,N<CR> (Assuming no alarm conditions)

3. To get a flow reading: !12,F<CR>The XFM will reply:

!12,50.0<CR> (Assuming the flow is at 50% FS)

4. Set the high alarm limit to 85% of full scale flow rate:

!12,A,H,85.0<CR>

The XFM will reply: !12,AH85.0<CR>

The global address can be used to change RS-485 address for a particular device with
unknown address:

1. Make sure only one device (which address must be changed) is connected to the
RS-485 network.

2. Type the memory write command with global address: !00,MW,7,XX[CR] where
XX, the new hexadecimal address, can be [01 – FF].

After assigning the new address, a device will accept commands with the new address.

Note: Address 00 is reserved for global addressing. Do not assign, the
global address for any device. When command with global address is
sent, all devices on the RS-485 bus execute the command but do not
reply with an acknowledge message.



Note: Do not assign the same RS-485 address for two or more
devices on the same RS-485 bus. If two or more devices with the same
address are connected to the one RS-485 network, a communication
collision will take place on the bus and communication errors will occur.



30

8.3 ASCII Commands Set

AALBORG XFM SOFTWARE INTERFACE COMMANDS

COMMAND

NAME

DESCRIPTION

No.

COMMAND SYNTAX

Command

Argument 1

Argument 2 Argument 3 Argument 4 Response

Flow

Requests the current flow

sensor reading in current EU

1

F <Value> (Actual flow in

current engineering units)

Diagnostic Enable / Disable LCD

Diagnostic messages (only

for LCD option).

Request current status of

the Diagnostic events, LED

status and LCD diagnostic

mode (enabled/disabled).

2 D

E (enable LCD

** Diagnostic Messages)

D:E

D (disable LCD

** Diagnostic Messages)

D:D

NO ARGUMENT

(read current status of

the diagnostic word)

D:0x0,L:9,E

0x0 – diagnostic word

9 - current LED status

E - LCD mode (enabled)

Roll back to

N

2

feature.

Enable / Disable Roll back

to N

2

feature.

3

N E

(enable Roll back to N

2

)

N:E

D

(enable Roll back to N

2

)*

N:D

NO ARGUMENT

(read current mode of

the N2 Roll back )

N:DOrN:E

Gas Select

Selects one of the ten

primary gas calibration

tables to use. Tables are

entered via the MEM

commands at time of

calibration.

4 G 0 (gas 0)*

to

9 (gas 9)

G0 through G9,

<Gas Name>

NO ARGUMENT

(read status)

G0 through G9,

<Gas Name>

Note: An “*” indicates power up default settings. An “**”indicates optional feature not available on all models.

31

COMMAND

NAME

DESCRIPTION

No.

COMMAND SYNTAX

Command

Argument 1 Argument 2 Argument 3

Argument 4 Response

Auto

Zero

Starts /reads the status of

the auto zero feature (Note:

The Z,N command can be

used only when absolutely

no flow thru the meter and

no earlier then 6 minutes after

power up. It can take several

minutes to complete. Unit will

not respond to other commands

when this is in progress.)

5

Z

N (do it now)

ZN

W (Write Zero to

EEPROM)

ZW (when done)

S (status while auto

zero in progress)

ZNI,<value> while Z,N

is in progress.

V (Display zero value) ZV,<zero value>

Flow

Alarms

Sets / reads the status of

the gas flow alarms.

Note: High and Low limits

have to be entered in the

%F.S. High alarm value

has to be more than Low

alarm value.

Alarm conditions:

Flow > High Limit = H

Flow < Low Limit = L

Low < Flow < High = N

6

A H (high flow limit) <Value> (0-100%FS)

AH<Value>

L (low flow limit)

<Value> (0-100%FS) AL<Value>

A (action delay in seconds) <Value> (0-3600 sec.)

AA:<Value>

E (enable alarm)

AE

D (disable alarm)* AD

R (read current status)

N (no alarm)

H (high alarm)

L (low alarm)

S (Read current settings) AS:M,L,H,D,B where:

M – mode (E/D)

L – Low settings (%FS)

H – High settings (%FS)

D – Action Delay (sec)

B – Latch mode (0-3)

B Block (Latch) mode <Value> (0-disabled*)

(1-enabl’d L)

(2-enabl’d H)

(3 –both L,H)

AB:<Value> where:

Value = 0 - 3

32

COMMAND

NAME

DESCRIPTION

No.

COMMAND SYNTAX

Command Argument 1

Argument 2

Argument 3 Argument 4 Response

Relay

Action

Assigns action of the two SPDT

relays. The coil is energized

when the condition specified by

an Argument 2 becomes true.

Argument 2:

N - no action, relay disabled*

T - totalizer reading > limit

H - high flow alarm

L - low flow alarm

R - Range between High &

Low alarms

M - Manual Relay overdrive

S - Read current status

7

R 1 (relay 1)

2 (relay 2)

N*

R1N or R2N

T

R1T or R2T

H

R1H or R2H

L R1L or R2L

R R1R or R2R

M R1M or R2M

S

RxN, RxT, RxH,

RxL, RxR , RxM

Totalizer Sets and controls action of the

flow totalizer.

NOTE: If Warm Up Delay option

is set to E (enabled) the Totalizer

will not totalize the flow during

first 6 minutes after power up.

8 T

Z (Reset to zero)

TZ

F (start totalizer at flow F.S.)

L (Limit gas volume in current E.U.)

<value>

(flow %FS)

TF<value>

<value>

(gas volume)

TL<value>

D (disable totalizer)

TD

E (enable totalizer) TE

R (read current totalizer volume)

<value> (in current EU)

W (Warm Up Delay)

E – enable

D – disable*

TW:E or TW:D

S (setting status)

TS: Mode, Start,

Limit, Warm Up

33

COMMAND

NAME

DESCRIPTION

No.

COMMAND SYNTAX

Command Argument 1

Argument 2

Argument 3 Argument 4

Response

K Factors

Applies a gas correction

factor to the currently

selected primary gas

calibration table.

(NOTE: does not work with

% F.S. engineering unit.)

See list of the internal

K-factors in the operating

manual.

9

K

D*(disable, sets K=1) KD

I (Internal K-factor) No argument

(enable previously set

internal K-factor)

KI,<value>,<Gas>

Gas Index (0 -35) KI,<Index>,<Gas>

U (user specified factor) No argument

(enable previously set

user K-factor)

KU,<value>

<value>

(decimal correction

factor) (0-1000)

KU,<value>

S (status)

SK, <Mode>, <Index>,

<Value> where:

Mode: D, I, U

Index: 0-35

Value: K-Factor value

34

COMMAND

NAME

DESCRIPTION

No.

COMMAND SYNTAX

Command

Argument 1

Argument 2 Argument 3 Argument 4 Response

Units

Set the units of

measure for gas

flow and totalizer

reading.

Note: The units

of the totalizer

output are not

per unit time.

10 U

% (% full scale)* U:%

mL/sec U:mL/sec

mL/min U:mL/min

mL/hr

U:mL/hr

L/sec

U:L/sec

L/min

U:L/min

L/hr U:L/hr

m3/sec

U:m3/sec

m3/min U:m3/min

m3/hr U:m3/hr

f3/sec U:f3/sec

f3/min U:f3/min

f3/hr

U:f3/hr

g/sec

U:g/sec

g/min

U:g/min

g/hr

U:g/hr

kg/sec U:kg/sec

kg/min

U:kg/min

kg/hr U:kg/hr

Lb/sec

U:Lb/sec

Lb/min

U:Lb/min

Lb/hr

U:Lb/hr

USER (user defined)

<value> (conversion

factor from L/min)

S - seconds

M – minutes

H – hours (Time base)

Y - use density

N – do not use

density

U:USER,<Factor>,

<Time base>,

<Density mode>

No Argument

<status>Returns current EU.

U,<EU name>

35

UART Error Codes:

1 - Not Supported Command or Back Door is not enabled.

2 - Wrong # of Arguments.

3 - Address is Out of Range (MR or MW commands).

4 - Wrong # of the characters in the Argument.

5 - Attempt to Alter Write Protected Area in the EEPROM.

6 - Proper Command or Argument is not found.

7 - Wrong value of the Argument.

8 - Reserved.

9 - Manufacture specific info EE KEY (wrong key or key is disabled).

COMMAND

NAME

DESCRIPTION

No.

COMMAND SYNTAX

Command Argument 1

Argument 2

Argument 3 Argument 4 Response

Maintenance

Timer

Hours since last time unit

was calibrated.

11 C

R (read timer)

<Value> (in Hours)

C(set timer to zero)

CC

Full Scale

Returns the full scale rated flow in

L/min. (Note: This term is not

multiplied by the current K factor)

12

E

<Value>

(in L/min)

LCD Back

Light

LCD Back Light control

(0-100.0%)

0 - off

100 - Maximum Intensity

13

B 0 to 100%

B:<Counts>

where:

Counts (0 – 4095)

B:<Value>

where:

Value (0 – 100.0)

No Argument

<Current settings>

Read

EEPROM

Memory

Reads the value in the

specified memory location.

14

MR 0000 to999

(Table Index)

<value>

Write

EEPROM

Memory

Writes the specified value to the

specified memory location. Use

Carefully, can cause unit to

malfunction. (Note: Some addresses

are write protected!)

15 MW 0000 to 999

(Table Index)

Value MW,XXX,<Value>

where:

XXX=Table Index

9. TROUBLESHOOTING

9.1 Common Conditions

Your XFM Digital Mass Flow Meter was thoroughly checked at numerous quality
control points during and after manufacturing and assembly operations. It was cal­ibrated according to your desired flow and pressure conditions for a given gas or
a mixture of gases.

It was carefully packed to prevent damage during shipment. Should you feel that
the instrument is not functioning properly, please check for the following common
conditions first:

Are all cables connected correctly? Are there any leaks in the installation? Is the
power supply correctly selected according to requirements? When several meters
are used a power supply with appropriate current rating should be selected.

Were the connector pinouts matched properly? When interchanging with other
manufacturers' equipment, cables and connectors must be carefully wired for cor­rect pin configurations. Is the pressure differential across the instrument sufficient?

36

37

9.2 Troubleshooting Guide

NO. INDICATION LIKELY REASON SOLUTION

1 No zero reading after

15 min. warm up time
and no flow condition.

Embedded temperature
has been changed.

Perform Auto Zero Procedure (see section

5.3.6 “Zero Calibration”).

2 Status LED indicator

and LCD Display
remains blank when
unit is powered up. No
response when flow is
introduced from analog
outputs 0-5 Vdc or
4-20 mA.

Power supply is bad or
polarity is reversed.

Measure voltage on pins 7 and 5 of the 15
pin D-connector. If voltage is out of
specified range, then replace power supply
with a new one. If polarity is reversed
(reading is negative) make correct
connection.

PC board is defective. Return XFM to factory for repair.

3 LCD Display reading or

/and analog output
0-5Vdc signal fluctuate
in wide range during
flow measurement.

Output 0-5 Vdc signal
(pins 2–1 of the D-con
nector) is shorted on
the GND or overloaded.

Check external connections to pin 2 – 1, of
the D-connector. Make sure the load
resistance is more than 1000 Ohm.

4 LCD Display reading

does correspond to the
correct flow range, but
0-5 Vdc output signal
does not change
(always the same read
ing or around zero).

Output 0-5Vdc
schematic is burned
out or damaged.

Return XFM to factory for repair.

Analog flow output
scale and offset
variable are corrupted.

Restore original EEPROM scale and offset
variable or perform analog output
recalibration (see section 7.3).

5 LCD Display reading

and 0-5 Vdc output
voltage do correspond
to the correct flow
range, but 4-20 mA
output signal does not
change (always the
same or reading
around 4.0 mA).

External loop is open or
load resistance more
than 500 Ohm.

Check external connections to pins 2 and
15 of the D-connector. Make sure the loop
resistance is less than 500 Ohm.

Output 4-20 mA
schematic is burned
out or damaged.

Return XFM to factory for repair.

6 Calibration is off (more

than ±1.0 % F.S.).

XFM has initial zero
shift.

Shut off the flow of gas into the XFM
(ensure gas source is disconnected and no
seepage or leak occurs into the meter).
Wait for 15 min. with no flow condition and
perform Auto Zero calibration Procedure
(see section 5.3.7 “Zero Calibration”).

7 LCD Display reading is

above maximum flow
range and output volt
age 0-5 Vdc signal is
more than 5.0 Vdc
when gas flows
through the XFM.

Sensor under
swamping conditions
(flow is more than 10%
above maximum flow
rate for particular
XFM).

Lower the flow through XFM within
calibrated range or shut down the flow
completely. The swamping condition will
end automatically.

PC board is defective. Return XFM to factory for repair.

38

NO. INDICATION LIKELY REASON SOLUTION

8 Gas flows through the

XFM, but LCD Display
reading and the output
voltage 0-5 Vdc signal
do not respond to flow.

The gas flow is too low
for particular model of
XFM.

Check maximum flow range on transducer’s
front panel and make required flow
adjustment.

XFM 17 models: RFE is
not connected properly
to the inlet fitting.

Unscrew the inlet compression fitting of the
meter and reinstall RFE (see section 6.2.2).
NOTE: Calibration accuracy can be affected.

Sensor or PC board is
defective.

Return XFM to factory for repair.

9 Gas does not flow

through the XFM with
inlet pressure applied
to the inlet fitting. LCD
Display reading and
output voltage 0-5 Vdc
signal show zero flow.

Filter screen obstructed
at inlet.

Flush clean or disassemble to remove
impediments or replace the filter screen
(see section 6.2).
NOTE: Calibration accuracy can be affected.

10 Gas flows through the

XFM, output voltage 0­5 Vdc signal does not
respond to flow
(reading near 1mV).

Direction of the gas
flow is reversed.

Check the direction of gas flow as indicated
by the arrow on the front of the meter and
make required reconnection in the
installation.

XFM is connected in the
installation with back
pressure conditions and
gas leak exist in the
system.

Locate and correct gas leak in the system. If
XFM has internal leak return it to factory for
repair.

11 The Status LED

indicator is rapidly
flashing with UMBER
color on /off.

Sensor temperature is
too low.

Make sure the ambient and gas
temperatures are within specified range
(above 5°C)

12 The Status LED indica

tor is rapidly flashing
with RED color on /off.

Sensor temperature is
too high.

Make sure the ambient and gas
temperatures are within specified range
(below 50°C)

13 The Status LED

indicator is rapidly
flashing with RED and
UMBER colors.

MCU temperature is too
high (overload).

Disconnect power from the XFM. Make sure
the ambient temperature is within specified
range (below 50°C). Let the device cool
down for at least 15 minutes. Apply power
to the XFM and check Status LED indication.
If overload condition will be indicated again
the unit has to be returned to the factory for
repair.

14 The Status LED

indicator is constantly
on with the RED light.

Fatal Error (EEPROM
or Auto Zero error).

Cycle the power on the XFM. If Status LED
still constantly on with RED light, wait 6
minutes and start Auto Zero function (see

5.3.7 Zero Calibration). If after Zero
Calibration the Fatal Error condition will be
indicated again the unit has to be returned
to the factory for repair.

9.3 Technical Assistance

Aalborg® Instruments will provide technical assistance over the phone to quali­fied repair personnel. Please call our Technical Assistance at 845-770-3000.
Please have your Serial Number and Model Number ready when you call.

39

Q

O2

= Q

a

= Q

r

X K = 1000 X 0.9926 = 992.6 sccm

where K = relative K factor to reference gas (oxygen to nitrogen)

1

d X C

p

where d = gas density (gram/liter)
C

p

= coefficient of specific heat (cal/gram)

Q

a

K

a

Q

r

K

r

where Qa= mass flow rate of an actual gas (sccm)
Q

r

= mass flow rate of a reference gas (sccm)

K

a

= K factor of an actual gas

K

r

= K factor of a reference gas

=

10. CALIBRATION CONVERSIONS FROM
REFERENCE GASES

The calibration conversion incorporates the K factor. The K factor is derived from
gas density and coefficient of specific heat. For diatomic gases:

=

K

=

K

gas

Note in the above relationship that d and Cp are usually chosen at the same con­ditions (standard, normal or other).

If the flow range of a Mass Flow Meter remains unchanged, a relative K factor is
used to relate the calibration of the actual gas to the reference gas.

For example, if we want to know the flow rate of oxygen and wish to calibrate
with nitrogen at 1000 SCCM, the flow rate of oxygen is:

Note: If particular K factor is activated via digital interface, the user
does not need to perform any conversion. All conversion computations
will be performed internally by MCU.



40

APPENDIX I

AALBORG7 XFM EEPROM Variables Rev.A0 [12/19/2006]

Gas Independent Variables

INDEX NAME DATA TYPE NOTES

0

BlankEEPROM char[10] Do not modify. Table Revision [PROTECTED]

1

SerialNumber char[20] Serial Number [PROTECTED]

2

ModelNumber char[20] Model Number [PROTECTED]

3

SoftwareVer char[10] Firmware Version [PROTECTED]

4

TimeSinceCalHr float Time since last calibration in hours.

5

Options1 uint Misc. Options*

6

BackLight int Back Light Level [0-4095]

7

AddressRS485 char[4] Two character address for RS485 only

8

GasNumber int Current Gas Table Number [0-9]

9

FlowUnits int Current Units of Measure [0-22]

10

AlarmMode char Alarm Mode ['E’- Enabled, 'D’ - Disabled]

11

LowAlarmPFS float Low Flow Alarm Setting [%FS] 0-Disabled

12

HiAlarmPFS float High Flow Alarm Setting [%FS] 0-Disabled

13

AlmDelay uint Flow Alarm Action Delay [0-3600sec] 0-Disabled

14

RelaySetting char[4] Relays Assignment Setting (N, T, H, L, R, M)

15

TotalMode char Totalizer Mode ['E’- Enabled, 'D’ - Disabled]

16

Total float Totalizer Volume in %*s (updated every 6 min)

17

TotalFlowStart float Start Totalizer at flow [%FS] 0 - Disabled

18

TotalVolStop float Totalizer Action Limit Volume [%*s] 0-Disabled

19

KfactorMode char D-Disabled, I-Internal, U-User Defined

20

KfactorIndex int Internal K-Factor Index [0-35]**

21

UserDefKfactor float User Defined K-Factor

22

UDUnitKfactor float K-Factor for User Defined Units of Measure

23

UDUnitTimeBase int User Defined Unit Time Base [1, 60, 3600 sec]

24

UDUnitDensity char User Defined Unit Density Flag [Y, N]

25

AoutScaleV float DAC 0-5 Vdc Analog Output Scale

26

AoutOffsetV float DAC 0-5 Vdc Analog Output Offset

27

AoutScale_mA float DAC 4-20mA Analog Output Scale

28

AoutOffset_mA float DAC 4-20mA Analog Output Offset

29

SensorZero uint DPW value for Sensor Zero [0-1023]

30

Klag [0] float DRC Lag Constant [Do Not Alter]

31

Klag [1] float DRC Lag Constant [Do Not Alter]

32

Klag [2] float DRC Lag Constant [Do Not Alter]

33

Klag [3] float DRC Lag Constant [Do Not Alter]

34

Klag [4] float DRC Lag Constant [Do Not Alter]

41

INDEX NAME DATA TYPE NOTES

35

Klag [5] float DRC Lag Constant [Do Not Alter]

36

Kgain[0] float Gain for DRC Lag Constant [Do Not Alter]

37

Kgain[1] float Gain for DRC Lag Constant [Do Not Alter]

38

Kgain[2] float Gain for DRC Lag Constant [Do Not Alter]

39

Kgain[3] float Gain for DRC Lag Constant [Do Not Alter]

40

Kgain[4] float Gain for DRC Lag Constant [Do Not Alter]

41

Kgain[5] float Gain for DRC Lag Constant [Do Not Alter]

42

Zero_T float Resistance when last AutoZero was done [0-4095 count]

43

Tcor_K float Resistance correction coefficient [PFS/count]

44

AlarmLatch uint Alarm Latch [0-3]

45

TotalWarmDisable char Sensor Warm Up period Totalizer [D/E]

46

Reserved1 uint Reserved

47

LCD_Diagnostic char LCD Diagnostic Mode: [E/D]**

48

Reserved2 uint

Flow Reading Averaging: [0,1,2]
(100, 250, 1000 ms), Default -1

49

N2_RollBack

char

Back to N2conversion mode: [E, D]

50

Reserved3 uint Reserved for Troubleshooting (do not change)

42

Calibration Table: Gas Dependent Variables.

Note: Values will be available for selected gas only.

INDEX NAME DATA TYPE NOTES

100

GasIdentifer char[20] Name of Gas [If not calibrated = “Uncalibrated”]

101

FullScaleFlow float Full Scale Range in l/min

102

StdTemp float Standard Temperature

103

StdPressure float Standard Pressure

104

StdDensity float Gas Standard Density

105

CalibrationGas char[20]

Name of Gas used for Calibration

[If not calibrated=[“Uncalibrated”]

106

CalibratedBy char[20] Name of person who performed actual calibration

107

CalibratedAt char[20] Name of Calibration Facility

108

DateCalibrated char[12] Calibration Date

109

DateCalibrationDue char[12] Date Calibration Due

110

K_N

2

float Gas Parameters: K-factor relative to N

2

111

K_F1 float Reserved

112

K_F1 float Reserved

113

SensorTbl[0][Sensor Value] uint Index 0: Must be 120 (zero value) Do not Alter!

114

SensorTbl[0][Flow] float Index 0: Must be 0.0 (zero PFS) Do not Alter!

115

SensorTbl[1][Sensor Value] uint 10.0%F.S. A/D value from sensor [counts].

116

SensorTbl[1][Flow] float Actual Flow in PFS [0.1].

117

SensorTbl[2][Sensor Value] uint 20.0%F.S. A/D value from sensor [counts].

118

SensorTbl[2][Flow] float Actual Flow in PFS [0.2].

119

SensorTbl[3][Sensor Value] uint 30.0%F.S. A/D value from sensor [counts].

120

SensorTbl[3][Flow] float Actual Flow in PFS [0.3].

121

SensorTbl[4][Sensor Value] uint 40.0%F.S. A/D value from sensor [counts].

122

SensorTbl[4][Flow] float Actual Flow in PFS [0.4].

123

SensorTbl[5][Sensor Value] uint 50.0%F.S. A/D value from sensor [counts].

124

SensorTbl[5][Flow] float Actual Flow in PFS [0.5].

125

SensorTbl[6][Sensor Value] uint 60.0%F.S. A/D value from sensor [counts].

126

SensorTbl[6][Flow] float Actual Flow in PFS [0.6].

127

SensorTbl[7][Sensor Value] uint 70.0%F.S. A/D value from sensor [counts].

128

SensorTbl[7][Flow] float Actual Flow in PFS [0.7].

129

SensorTbl[8][Sensor Value] uint 80.0%F.S. A/D value from sensor [counts].

130

SensorTbl[8][Flow] float Actual Flow in PFS [0.8].

131

SensorTbl[9][Sensor Value] uint 90.0%F.S. A/D value from sensor [counts].

132

SensorTbl[9][Flow] float Actual Flow in PFS [0.9].

133

SensorTbl[10][Sensor Value] uint 100.0%F.S. A/D value from sensor [counts].

134

SensorTbl[10][Flow] float Flow in PFS. Should be 1.0 Do not Alter!

43

APPENDIX II INTERNAL "K" FACTORS



CAUTION: K-Factors at best are only an approximation. K factors should not

be used in applications that require accuracy better than +/- 5 to 10%.

INDEX ACTUAL GAS

K Factor
Relative

to N

2

Cp

[Cal/g]

DENSITY

[g/I]

0 Acetylene C2H2 0.5829 .4036 1.162
1 Air 1.000 0.24 1.293
2 Allene (Propadiene) C3H4 0.4346 0.352 1.787

3 Ammonia NH

3

.7310 .492 .760

4 Argon Ar 1.4573 .1244 1.782

5 Arsine AsH3 0.6735 0.1167 3.478

6 Boron Trichloride BCl3 0.4089 0.1279 5.227

7 Boron Triflouride BF3 0.5082 0.1778 3.025

8 Bromine Br2 0.8083 0.0539 7.130

9 Boron Tribromide Br3 0.38 0.0647 11.18

10 Boromine Pentaflouride BrF5 0.26 0.1369 7.803

11 Boromine Triflouride BrF3 0.3855 0.1161 6.108

12 Bromotriflouromethane CBrF3 0.3697 0.1113 6.644

13 1,3-Butadiene C4H6 0.3224 0.3514 2.413

14 Butane C4H

10

.2631 .4007 2.593

15 1-Butane C4H8 0.2994 0.3648 2.503

16 2-Butane C4H8 CIS 0.324 0.336 2.503

17 2-Butane C4H8 TRANS 0.291 0.374 2.503

18 Carbon Dioxide CO

2

.7382 .2016 1.964

19 Carbon Disulfide CS

2

0.6026 0.1428 3.397

20

Carbon Monoxide C

O

1.00 .2488 1.250

21 Carbon Tetrachloride CCl4 0.31 0.1655 6.860

22 Carbon Tetrafluoride (Freon-14) CF4 0.42 0.1654 3.926

23 Carbonyl Fluoride COF2 0.5428 0.1710 2.945

24 Carbonyl Sulfide COS 0.6606 0.1651 2.680

25 Chlorine Cl

2

0.86 0.114 3.163

26 Chlorine Trifluoride ClF3 0.4016 0.1650 4.125
27 Chlorodifluoromethane (Freon-22) CHClF2 0.4589 0.1544 5.326

28 Chloroform CHCl

3

0.3912 0.1309 5.326

29 Chloropentafluoroethane (Freon -115) C2ClF5 0.2418 0.164 6.892

30 Chlorotrifluoromethane (Freon-13) CClF3 0.3834 0.153 4.660

31 Cyanogen C2N2 0.61 0.2613 3.322
32 Helium He 1.454 1.241 .1786
33 Hydrogen H

2

1.0106 3.419 .0899

34 Hydrogen H2(> 100 L/min) 1.92 3.419 0.0899

35 Oxygen O2 0.9926 0.2193 1.427

44

APPENDIX III GAS FACTOR TABLE (“K FACTORS”)



CAUTION: K-Factors at best are only an approximation. K factors should not

be used in applications that require accuracy better than +/- 5 to 10%.

ACTUAL GAS

K FACTOR

Relative to N

2

Cp

[Cal/g]

Density

[g/I]

Acetylene C2H

2

.5829 .4036 1.162
Air 1.0000 .240 1.293
Allene (Propadiene) C3H

4

.4346 .352 1.787
Ammonia NH

3

.7310 .492 .760
Argon Ar (<=10 L/min)

Argon AR-1 (>=10 L/min)

1.4573

1.205

.1244
.1244

1.782

1.782

Arsine AsH

3

.6735 .1167 3.478
Boron Trichloride BCl

3

.4089 .1279 5.227
Boron Trifluoride BF

3

.5082 .1778 3.025
Bromine Br

2

.8083 .0539 7.130
Boron Tribromide Br

3

.38 .0647 11.18
Bromine PentaTrifluoride BrF

5

.26 .1369 7.803
Bromine Trifluoride BrF

3

.3855 .1161 6.108

Bromotrifluoromethane (Freon-13 B1) CBrF

3

.3697 .1113 6.644

1,3-Butadiene C4H

6

.3224 .3514 2.413

Butane C4H

10

.2631 .4007 2.593

1-Butene C4H

8

.2994 .3648 2.503

2-Butene C4H8 CIS

.324 .336 2.503

2-Butene C4H8TRANS

.291 .374 2.503

Carbon Dioxide CO2 (<10 L/min)
Carbon Dioxide CO

2

-1 (>10 L/min)

.7382
.658

.2016
.2016

1.964

1.964

Carbon Disulfide CS

2

.6026 .1428 3.397

Carbon Monoxide C0

1.00 .2488 1.250

Carbon Tetrachloride CCl

4

.31 .1655 6.860

Carbon Tetrafluoride (Freon-14)CF

4

.42 .1654 3.926

Carbonyl Fluoride COF

2

.5428 .1710 2.945

Carbonyl Sulfide COS

.6606 .1651 2.680

Chlorine Cl

2

.86 .114 3.163

Chlorine Trifluoride ClF

3

.4016 .1650 4.125

Chlorodifluoromethane (Freon-22)CHClF

2

.4589 .1544 3.858

Chloroform CHCl

3

.3912 .1309 5.326

Chloropentafluoroethane(Freon-115)C2ClF

5

.2418 .164 6.892

Chlorotrifluromethane (Freon-13) CClF

3

.3834 .153 4.660

CyanogenC2N

2

.61 .2613 2.322

CyanogenChloride CICN

.6130 .1739 2.742

Cyclopropane C3H

5

.4584 .3177 1.877

45

ACTUAL GAS

K FACTOR

Relative to N

2

Cp

[Cal/g]

Density

[g/I]

Deuterium D

2

1.00 1.722 1.799

Diborane B2H

6

.4357 .508 1.235

Dibromodifluoromethane CBr2F

2

.1947 .15 9.362

Dichlorodifluoromethane (Freon-12) CCl2F

2

.3538 .1432 5.395

Dichlofluoromethane (Freon-21) CHCl2F

.4252 .140 4.592

Dichloromethylsilane (CH3)2SiCl

2

.2522 .1882 5.758

Dichlorosilane SiH2Cl

2

.4044 .150 4.506

Dichlorotetrafluoroethane (Freon-114) C2Cl2F

4

.2235 .1604 7.626

1,1-Difluoroethylene (Freon-1132A) C2H2F

2

.4271 .224 2.857

Dimethylamine (CH3)2NH

.3714 .366 2.011

Dimethyl Ether (CH3)2O

.3896 .3414 2.055

2,2-Dimethylpropane C3H

12

.2170 .3914 3.219

Ethane C2H

6

.50 .420 1.342

Ethanol C2H6O

.3918 .3395 2.055

Ethyl Acetylene C4H

6

.3225 .3513 2.413

Ethyl Chloride C2H5Cl

.3891 .244 2.879

Ethylene C2H

4

.60 .365 1.251

Ethylene Oxide C2H4O

.5191 .268 1.965

Fluorine F

2

.9784 .1873 1.695

Fluoroform (Freon-23) CHF

3

.4967 .176 3.127

Freon-11 CCl3F

.3287 .1357 6.129

Freon-12 CCl2F

2

.3538 .1432 5.395

Freon-13 CClF

3

.3834 .153 4.660

Freon-13B1 CBrF

3

.3697 .1113 6.644

Freon-14 CF

4

.4210 .1654 3.926

Freon-21 CHCl2F

.4252 .140 4.592

Freon-22 CHClF

2

.4589 .1544 3.858

Freon-113 CCl2FCClF

2

.2031 .161 8.360

Freon-114 C2Cl2F

4

.2240 .160 7.626

Freon-115 C2ClF

5

.2418 .164 6.892

Freon-C318 C4F

8

.1760 .185 8.397

Germane GeH

4

.5696 .1404 3.418

Germanium Tetrachloride GeCl

4

.2668 .1071 9.565

Helium He (=<10 L/min)
Helium He-1 (>50 L/min)
Helium He-2 (>10-50 L/min)

1.454

2.43

2.05

1.241

1.241

1.241

.1786
.1786
.1786

Hexafluoroethane C2F6(Freon-116)

.2421 .1834 6.157

Hexane C6H

14

.1792 .3968 3.845

Hydrogen H2-1 (=<10 L/min)
Hydrogen H

2

-2 (>10-100 L)

Hydrogen H

2

-3 (>100 L)

1.0106

1.35

1.9

3.419

3.419

3.419

.0899
.0899
.0899

46

ACTUAL GAS

K FACTOR

Relative to N

2

Cp

[Cal/g]

Density

[g/I]

Hydrogen Bromide HBr

1.000 .0861 3.610

Hydrogen Chloride HCl

1.000 .1912 1.627

Hydrogen Cyanide HCN

.764 .3171 1.206

Hydrogen Fluoride HF

.9998 .3479 .893

Hydrogen Iodide HI

.9987 .0545 5.707

Hydrogen Selenide H2Se

.7893 .1025 3.613

Hydrogen Sulfide H2S

.80 .2397 1.520

Iodine Pentafluoride IF

5

.2492 .1108 9.90

Isobutane CH(CH3)

3

.27 .3872 3.593

Isobutylene C4H

6

.2951 .3701 2.503

Krypton Kr

1.453 .0593 3.739

Methane CH4(<=10 L/min)
Methane CH

4

-1 (>=10 L/min)

.7175
.75

.5328
.5328

.715
.715

Methanol CH

3

.5843 .3274 1.429

Methyl Acetylene C3H

4

.4313 .3547 1.787

Methyl Bromide CH2Br

.5835 .1106 4.236

Methyl Chloride CH3Cl

.6299 .1926 2.253

Methyl Fluoride CH3F

.68 .3221 1.518

Methyl Mercaptan CH3SH

.5180 .2459 2.146

Methyl Trichlorosilane (CH3)SiCl

3

.2499 .164 6.669

Molybdenum Hexafluoride MoF

6

.2126 .1373 9.366

Monoethylamine C2H5NH

2

.3512 .387 2.011

Monomethylamine CH3NH

2

.51 .4343 1.386

Neon NE

1.46 .246 .900

Nitric Oxide NO

.990 .2328 1.339

Nitrogen N

2

1.000 .2485 1.25

Nitrogen Dioxide NO

2

.737 .1933 2.052

Nitrogen Trifluoride NF

3

.4802 .1797 3.168

Nitrosyl Chloride NOCl

.6134 .1632 2.920

Nitrous Oxide N2O

.7128 .2088 1.964

Octafluorocyclobutane (Freon-C318) C4F

8

.176 .185 8.397

Oxygen O

2

.9926 .2193 1.427

Oxygen Difluoride OF

2

.6337 .1917 2.406

Ozone

.446 .195 2.144

Pentaborane B5H

9

.2554 .38 2.816

Pentane C5H

12

.2134 .398 3.219

Perchloryl Fluoride ClO3F

.3950 .1514 4.571

Perfluoropropane C3F

8

.174 .197 8.388

Phosgene COCl

2

.4438 .1394 4.418

Phosphine PH

3

.759 .2374 1.517

47

ACTUAL GAS

K FACTOR

Relative to N

2

Cp

[Cal/g]

Density

[g/I]

Phosphorous Oxychloride POCl

3

.36 .1324 6.843

Phosphorous Pentafluoride PH

5

.3021 .1610 5.620

Phosphorous Trichloride PCl

3

.30 .1250 6.127

Propane C3H

8

.35 .399 1.967

Propylene C3H

6

.40 .366 1.877

Silane SiH

4

.5982 .3189 1.433

Silicon Tetrachloride SiCl

4

.284 .1270 7.580

Silicon Tetrafluoride SiF

4

.3482 .1691 4.643

Sulfur Dioxide SO

2

.69 .1488 2.858

Sulfur Hexafluoride SF

6

.2635 .1592 6.516

Sulfuryl Fluoride SO2F

2

.3883 .1543 4.562

Tetrafluoroethane (Forane 134A) CF3CH2F

.5096 .127 4.224

Tetrafluorohydrazine N2F

4

.3237 .182 4.64

Trichlorofluoromethane (Freon-11) CCl3F

.3287 .1357 6.129

Trichlorosilane SiHCl

3

.3278 .1380 6.043

1,1,2-Trichloro-1,2,2 Trifluoroethane
(Freon-113) CCl

2

FCClF

2

.2031 .161 8.36

Triisobutyl Aluminum (C4H9)AL

.0608 .508 8.848

Titanium Tetrachloride TiCl

4

.2691 .120 8.465

Trichloro Ethylene C2HCl

3

.32 .163 5.95

Trimethylamine (CH3)3N

.2792 .3710 2.639

Tungsten Hexafluoride WF

6

.2541 .0810 13.28

Uranium Hexafluoride UF

6

.1961 .0888 15.70

Vinyl Bromide CH2CHBr

.4616 .1241 4.772

Vinyl Chloride CH2CHCl

.48 .12054 2.788

Xenon Xe

1.44 .0378 5.858

48

APPENDIX IV COMPONENT DIAGRAM

TOP COMPONENT SIDE

Aug. 09, 2007

49

BOTTOM COMPONENT SIDE

Aug 09, 2007

APPENDIX V

DIMENSIONAL DRAWINGS

XFM WITHOUT READOUT

50

XFM WITH PROFIBUS CAPABILITY

51

XFM WITH READOUT OPTION

52

APPENDIX VI

53

NOTE: Follow Return Procedures In Section 1.3.

WARRANTY

Aalborg7 Mass Flow Systems are warranted against parts and
workmanship for a period of one year from the date of purchase. Calibrations
are warranted for up to six months after date of purchase, provided calibra­tion seals have not been tampered with. It is assumed that equipment select­ed by the customer is constructed of materials compatible with gases used.
Proper selection is the responsibility of the customer. It is understood that
gases under pressure present inherent hazards to the user and to equip­ment, and it is deemed the responsibility of the customer that only operators
with basic knowledge of the equipment and its limitations are permitted to
control and operate the equipment covered by this warranty. Anything to the

contrary will automatically void the liability of Aalborg7 and the provisions of
this warranty. Defective products will be repaired or replaced solely at the

discretion of Aalborg7 at no charge. Shipping charges are borne by the cus­tomer.This warranty is void if the equipment is damaged by accident or mis-

use, or has been repaired or modified by anyone other than Aalborg7 or fac-
tory authorized service facility. This warranty defines the obligation of

Aalborg7 and no other warranties expressed or implied are recognized.

TRADEMARKS

Aalborg®-is a registered trademark of Aalborg Instruments & Controls.
Buna

®

-is a registered trademark of DuPont Dow Elastometers.

Kalrez®-is a registered trademark of DuPont Dow Elastomers.

Neoprene

®

-is a registered trademark of DuPont.

Viton®-is a registered trademark of Dupont Dow Elastomers L.L.C.