Aalborg DFM Operating Manual
OPERATING MANUAL
DFM
Digital Mass Flow Meter
Technical Data Sheet No.: TD0501M Rev. E
Date of Issue: May 2017
Aalborg7is a registered trademark of Aalborg Instruments & Controls.
NOTE: Aalborg reserves the right to change designs and dimensions at its sole
discretion at any time without notice. For certified dimensions please contact Aalborg7.
TABLE OF CONTENTS
1. UNPACKING THE DFM 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 Output 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 Programming DFM using LCD and Keypad................................................
5.3.1 Changing Units of Measurement for Temperature & Pressure Reading.....
5.3.2 Monitoring DFM peripheries settings.........................................................
5.3.3 DFM Main Menu.........................................................................................
5.3.4 Gas Flow Engineering Units Settings..........................................................
5.3.5 Gas Table Settings......................................................................................
5.3.6 Totalizer Settings........................................................................................
5.3.7 Alarm Settings...........................................................................................
5.3.8 Relay Assignment Settings........................................................................
5.3.9 K Factors Settings.....................................................................................
5.3.10 Zero Calibration..........................................................................................
5.3.11 Flow Conditions Settings...........................................................................
5.3.12 LCD Backlit Energy-saving Setting............................................................
5.4 Flow, Temperature, Pressure Output Signals Configuration......................
6. MAINTENANCE....................................................................
6.1 Introduction................................................................................................
6.2 Flow Path Cleaning....................................................................................
6.2.1 Restrictor Flow Element (RFE)..................................................................
6.2.2 DFM 26/27 Models....................................................................................
6.2.3 DFM 36/37/46/47 models..........................................................................
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7. CALIBRATION PROCEDURES..................................................
7.1 Flow Calibration........................................................................................
7.2 Gas Flow Calibration of DFM Mass Flow Meters......................................
7.2.1 Connections and Initial Warm Up.............................................................
7.2.2 ZERO Check/Adjustment..........................................................................
7.2.3 Gas Linearization Table Adjustment.........................................................
7.3 Analog output Calibration of DFM 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............................................
7.3.4 Gas temperature 0-5 Vdc analog output calibration (DFM 27/37/47)......
7.3.5 Gas temperature 4-20 mA analog output calibration (DFM 27/37/47).....
7.3.6 Gas pressure 0-5 Vdc analog output calibration (DFM 27/37/47)............
7.3.7 Gas pressure 4-20 mA analog output calibration (DFM 27/37/47)..........
7.4 Temperature or/and Pressure sensor 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 DFM 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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46
46
47
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1. UNPACKING THE DFM MASS FLOW METER
1.1 Inspect Package for External Damage
Your DFM 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 equip-
ment 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 DFM 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.
Caution: It is the users 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.
1
2
Attitude limit of Mass Flow Meter is ±15deg from 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 DFM 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 contaminants. Be sure to observe the direction
of gas flow as indicated by the arrow on the front of the meter when connecting
the gas system to be monitored. 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 according to the manufacturer's
instructions to one and one quarter turns. Avoid over tightening which will seriously damage the Restrictor Flow Elements (RFE's)!
Caution: For models DFM 27/37/47 (Multi Parameter versions)
the maximum pressure in the gas line should not exceed 100 PSIA
(6.8 bars). Applying pressure above 100 PSIA (6.8 bars) for
extended periods of time will seriously damage the pressure sensor.
Burst pressure is 200 PSIA (13.6 bar)!
DFM transducers are supplied with standard 1/4 inch (DFM 26/27 and 36/37) or
3/8 inch (DFM 46/47), 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.
Using a Helium Leak Detector or other equivalent method perform a thorough
leak test of the entire system. (All DFM's are checked prior to shipment for leakage within stated limits. See specifications in this manual.)
2.2 Electrical Connections
DFM is supplied with a 25 pin "D" connector. Pin diagram is presented in figure b-1.
2.2.1 Power Supply Connections
DFM transducers are supplied for three different power supply options:
±15Vdc (bipolar power supply)
DC Power (+) --------------- pin 1 of the 25 pin "D" connector
DC Power Common --------------- pin 18 of the 25 pin "D" connector
DC Power (-) --------------- pin 14 of the 25 pin "D" connector
3
+12Vdc or +24Vdc (unipolar power supply)
DC Power (+) --------------- pin 1 of the 25 pin "D" connector
DC Power (-) --------------- pin 18 of the 25 pin "D" connector
Caution: DO NOT CONNECT 24Vdc POWER SUPPLY UNLESS YOUR
DFM METER WAS ORDERED AND CONFIGURED FOR 24Vdc!
(See power requirements label at the rear of the DFM meter)
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 that the wiring
and the polarity of the power supply is correct before turning the power
ON. Wiring error may cause damage or faulty operation.
DFM series Mass Flow Meters are equipped with either calibrated 0-5 VDC (0-10
VDC optional) or calibrated 4-20 mA output signals (jumper selectable). This linear output signal represents 0-100% of the flow meter's full scale range. Multi
Parameter versions (DFM 27/37/47) are in addition equipped with either a calibrated 0-5 VDC (0-10VDC optional) or a calibrated 4-20 mA output signal (jumper
selectable) for pressure and temperature. Pressure linear output signal represents
0-100PSIA (46.9 kPa). Temperature linear output signal represents 0-50
F
C.
Warning: All 4-20 mA current loop outputs are 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 25 pin "D" connector
Minus (-) ------------------- pin 15 of the 25 pin "D" connector
Temperature 0-5 VDC or 4-20 mA output signal connection
(For DFM 27/37/47 only):
Plus (+) -------------------- pin 3 of the 25 pin "D" connector
Minus (-) -------------------- pin 16 of the 25 pin "D" connector
Pressure 0-5 VDC or 4-20 mA output signal connection
(For DFM 27/37/47 only):
Plus (+) -------------------- pin 4 of the 25 pin "D" connector
Minus (-) -------------------- pin 17 of the 25 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 is available) and provides access to applicable internal data including: flow, temperature, pressure
reading, auto zero, totalizer and alarm settings, gas table, conversion factors and
engineering units selection, dynamic response compensation and linearization
table adjustment.
Communication Settings:
Baud rate: -------- 9600 baud
Stop bit: -------- 1
Data bits: -------- 8
Parity: -------- None
Flow Control: -------- None
RS-485 communication interface connection:
The RS485 converter/adapter has to be configured for: multidrop, 2 wire, half
duplex mode. The transmitter circuit has to be enabled by TD or RTS (depending
on which is available on the converter/adapter). Settings for the receiver circuit
usually should follow the selection made for the transmitter circuit in order to
eliminate echo.
RS-485 T(-) or R(-) -------- pin 11 of the 25 pin "D" connector (-)
RS-485 T(+) or R(+) -------- pin 24 of the 25 pin "D" connector (+)
RS-485 GND (if available) -------- pin 20 of the 25 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 11 of the 25 pin "D" connector (TX)
RS-232 TX
(pin 3 on the DB9 connector) -------- pin 24 of the 25 pin "D" connector (RX)
RS-232 GND
(pin 5 on the DB9 connector) -------- pin 20 of the 25 pin "D" connector (GND)
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PIN FUNCTION
1 +15 Vdc (Optional +12 or +24 Vdc) Power Supply
2 0 5 Vdc or 4-20mA Flow Signal Output
3 0 5 Vdc or 4-20mA Temperature Signal Output (Optional)
4 0 5 Vdc or 4-20mA Pressure Signal Output (Optional)
5 (reserved)
6 (reserved)
7 (reserved)
8 Relay No. 1 - Common Contact
9 Relay No. 1 - Normally Open Contact
10 Relay No. 2 - Normally Closed Contact
11 RS485 (-) (Optional RS232 TX)
12 (No Connection)
13 Common
14 -15 VDC Power Supply (Only for ±15Vdc option)
15 Common, Signal Ground For Pin 2 (4-20 mA return)
16 Common, Signal Ground For Pin 3 (4-20 mA return)
17 Common, Signal Ground For Pin 4 (4-20 mA return)
18 Common, Power Supply (- DC power for 12 and 24 Vdc)
19 Common
20 RS232 Signal GND (RS-485 GND Optional)
21 Relay No. 1 - Normally Closed Contact
22 Relay No. 2 - Common Contact
23 Relay No. 2 - Normally Open Contact
24 RS485 (+) (Optional RS232 RX)
25 Chassis Ground
Figure b-1, DFM 25 Pin "D" Connector Configuration.
IMPORTANT NOTES: In general, "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 400mA 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).
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Use of the DFM flow transducer in a manner other than that specified in this manual or in writing from Aalborg7, may impair the protection provided by the equipment.
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 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 DFM model Mass Flow Meter incorporates a Digital Signal
Processor (DSP) and non-volatile memory that stores all hardware specific variables and up to 10 different calibration tables. Multi parameter flow meters
(Models: 27/37/47) provide accurate data on three different fluid parameters:
= flow
= pressure
= temperature
The flow rate can be displayed in volumetric flow or mass flow engineering units
for standard or actual (temperature, pressure) conditions. Flow meters can be
programmed locally via the four button keypad and LCD, or remotely, via the RS232/RS-485 interface. DFM flow meters support various functions including: flow
totalizer, flow, temperature, pressure alarms, automatic zero adjustment, 2 SPDT
relays output, 0-5 Vdc / 0-10 Vdc / 4-20 mA analog outputs for flow, pressure and
temperature.
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4. SPECIFICATIONS
FLOW MEDIUM: Please note that DFM Mass Flow Meters are designed to work
with clean gases only. Never try to measure flow rates of
liquids with any DFM.
CALIBRATIONS: Performed at standard conditions [14.7 psia (101.4 kPa) and
70
F
F (21.1 FC)] unless otherwise requested or stated.
ENVIRONMENTAL (PER IEC 664):
Installation Level II; Pollution Degree II.
FLOW ACCURACY FOR DFM 27/37/47 (INCLUDING LINEARITY):
0
F
C to 50 FC and 5 to 100 psia (34.5 - 689.5 kPa): ±1% of
full scale (F.S.)
FLOW ACCURACY FOR DFM 26/36/46 (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:
DFM 26/27: 300ms time constant; approximately 1 second
to within ±2% of set flow rate for 25% to 100% of full
scale flow.
DFM 36/46/37/47: 600ms time constant; approximately 2
seconds to within ±2% of set flow rate for 25% to 100% of
full scale flow.
MAXIMUM BURST PRESSURE:
DFM 26/36/46: 1000 psig (6895 kPa gauge).
DFM 27/37/47: 200 psig (1379 kPa gauge).
PRESSURE MEASUREMENT RANGE:
0 to 100 psia (689.5 kPa absolute).
P (absolute) = P (gauge) + P (atmospheric)
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PRESSURE MEASUREMENT ACCURACY:
±1% of F.S.
MAXIMUM PRESSURE DROP:
8 psi (at 100 L/min flow). See Table IV for pressure drops
associated with various models and flow rates.
TEMPERATURE MEASUREMENT RANGE:
0
F
C to 50 FC.
TEMPERATURE MEASUREMENT ACCURACY:
±1
F
C.
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 0-10Vdc (6000 ohms min impedance);
Linear 4-20 mA (500 ohms maximum loop resistance).
Maximum noise 20mV peak to peak (for 0-5 Vdc output).
TRANSDUCER INPUT POWER:
May be configured for three different options:
Bipolar ±15Vdc (±200 mA maximum);
Unipolar +12Vdc (300 mA maximum);
Unipolar +24Vdc (250 mA maximum);
Circuit boards have built-in polarity reversal protection.
Resettable fuses provide power input protection.
WETTED MATERIALS:
316 stainless steel, 416 stainless steel, VITON7 O-rings;
BUNA-N7, NEOPRENE7 or KALREZ7 O-rings are optional.
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Aalborg7 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 DFM 26/27: standard 1/4" compression fittings,
Model DFM 36/37: standard 1/4" compression fittings,
Model DFM 46/47: standard 3/8" compression fittings.
Optional 1/8" or 3/8" compression fittings and 1/4" VCR7 fittings are available.
DISPLAY: 128 x 64 graphic LCD with backlight (up to 8 lines of text).
User selectable backlight saver.
CALIBRATION OPTIONS:
Standard is one 10 points NIST calibration. Optional, up to 9
additional calibrations may be ordered at additional charge.
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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Table I DFM 26/27 Low Flow Mass Flow Meters*
Table II DFM 36/37 Medium Flow Mass Flow Meters *
Table III DFM 46 High Flow Mass Flow Meters *80
* Flow rates are stated for Nitrogen at STP conditions [i.e. 70
F
F (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 [N
2
]
01 0 to 10 07 0 to 1
02 0 to 20 08 0 to 2
03
0 to 50
09
0 to 5
04 0 to 100 10
0 to 10
05
0 to 200
06 0 to 500
CODE standard liters/min [N2]
11
0 to 15
30 20
31 30
32 40
33 50
CODE standard liters/min [N2]
40 60
41 80
42 100
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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]
DFM 26/27 up to 10 25 0.04
0.276
DFM 36/37
20 300 0.44 3.03
30 800 1.18 8.14
40 1480 2.18 15.03
50 2200 3.23 22.3
DFM 46/47
60 3100 4.56
31.4
100 5500 8.08 55.7
MODEL WEIGHT SHIPPING WEIGHT
DFM 26/27 transmitter 2.20 lbs (1.00 kg)
3.70 lbs (1.68 kg)
DFM 36/46/37/47 transmitter 2.95 lbs (1.33 kg)
4.34 lbs (1.97 kg)
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5. OPERATING INSTRUCTIONS
5.1 Preparation and Warm Up
It is assumed that the Digital 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. After two seconds the LSD display switches to the main screen
with the following information:
= Temperature and Pressure reading (for models DFM 27/37/47 only).
= Mass Flow reading in current engineering units.
= Current Gas Table and Gas Name.
= Totalizer Volume reading in current volume based engineering units.
= Totalizer , Alarm, and Relays status.
DFM Main Screen
Note: Allow the Digital Mass Flow Meter to warm-up for a minimum of
15 minutes.
During initial powering of the DFM transducer, the flow output signal will be indicating a higher than usual output. This is an indication that the DFM transducer
has not yet attained it's minimum operating temperature. This condition will automatically cancel within a few minutes and the transducer should eventually zero.
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.
,
F
F
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5.3 Programming DFM using LCD and Keypad
All features of the flow meter can be accessed via the local four button keypad and
LCD.The LCD incorporates an energy-saving auto shut-off backlit feature. If
enabled, after 15 minutes of operation without user intervention the LCD backlit
turns off. In order to turn on the LCD backlit press any key on the keypad. The LCD
backlit energy-saving auto shut-off feature can be disabled or enabled by user (see
p. 5.3.12 "LCD backlit Energy-saving Setting").
5.3.1 Changing Units of measurement for
Temperature and Pressure reading
By default after power up the temperature reading is displayed in
F
F and pressure
in PSI. Pressing (u) [Enter] button from main screen will alter the units of measure to
F
C for temperature and kPa for pressure reading respectively. In order to
change units of measure back to
F
F for temperature and PSI for pressure press
(u) [Enter] button while in the main screen one more time.
5.3.2 Monitoring DFM Peripheries Settings
The last row at the bottom of the main LCD screen reflects settings and status for
Totalizer, Flow Alarm, and Relays (see Figure b-2).
Totalizer Status:
TOT: R - totalizer is running (Enabled).
TOT: S - totalizer is stopped (Disabled).
Flow Alarm Status:
A: S - flow alarm is disabled.
A: R,N - flow alarm is enabled and currently there are no alarm conditions.
A: R,L - flow alarm is enabled and currently there is Low alarm condition.
A: R,H - flow alarm is enabled and currently there is High alarm condition.
F
F
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Relay Settings:
N - No assignment (relay is not assigned to any events).
H - High Flow Alarm condition.
L - Low Flow Alarm condition.
R - Range between High and Low Flow Alarm condition.
T - Totalizer reached set limit.
A - High Temperature Alarm condition.
B - Low Temperature Alarm condition.
C - High Pressure Alarm condition.
D - Low Pressure Alarm condition.
Continued pressing of the (p) [Up] button from the main screen will switch the
status line to display the following information:
- Calibrated Full scale range in standard L/min for current Gas Table.
- Device Digital Communication interface type (RS-485 or RS-232).
- Device RS-485 address (two hexadecimal characters).
- Device Zero DAC counts (for troubleshooting purposes).
- Device Sensor Average ADC counts (for troubleshooting purposes).
- Device Sensor Compensated ADC counts
(for troubleshooting purposes).
Note: Pressing the (q) [Dn] button from any of the status line will
switch the status display to one step back.
5.3.3 DFM Main Menu
Pressing of the (t) [Esc] button from the main screen will switch the display to
the Main Menu. The following screen will appear:
Figure b-3, DFM Main Menu Screen
Pressing of the (p) [Up] or (q) [Dn] buttons allows the user to scroll up or down
the menu options. Press (u) [Enter] button to select the highlighted option of the
menu.
,
i
15
The following menu options are available:
1. Units of Measure -
View or Change the Units of Measure for Flow process variable.
2. Gas Table Select -
View or Change the Gas Table.
3. Totalizer -
View or Change settings for Totalizer.
4. Alarm Settings -
View or Change settings for Flow , Pressure and Temperature Alarm.
5. Relay Action -
View or Change settings for each of two available Relays.
6. K Factors -
View or Change settings for User defined or Internal K Factors.
7. Zero Calibration -
Initiate Automatic Sensor Zero Calibration.
8. Flow Conditions -
Allows the user to set the Actual or Standard Flow conditions.
9. BackLight Timer -
Allows the user to turn On/Off the Energy-saving for LCD backlit.
10. Exit -
Returns to the Main Screen with process variables reading.
Note: Pressing the [Esc] button from any level of the Menu will switch
the menu to one level higher (up to Main Screen).
5.3.4 Gas Flow Engineering Units Settings
While in the Main Menu scroll with (p) [Up] or (q) [Dn] buttons to highlight the
Units of Measure option and press the (u) [Enter] button. The following screen
will appear:
Figure b-4, DFM Units of Measure Screen
,
i
The following Engineering Units menu options are available:
1. % F.S. - percent of full scale.
2. L/min - Liters per minute.
3. L/h - Liters per hour.
4. mL/min- milliliters per minute.
5. mL/h - milliliters per hour.
6. SCFH - cubic feet per hour.
7. SCFM - cubic feet per minute.
8. LbPH - pounds per hour.
9. LbPM - pounds per minute.
10. User - User defined Unit of Measure.
11. Exit - Exit to Main Menu
Selecting option 1 to 9 sets the corresponding Unit of Measure and switches the
LCD back to Main Menu.
Note: Once Flow Unit of Measure is changed the Totalizer's Volume
based Unit of Measure will be changed automatically.
If the User defined Unit of Measure option is selected the following screen will
appear:
Figure b-5, User Defined Unit of Measure Screen (K factor)
In order to specify the User Defined Unit of Measure user has to set three key
parameters:
K factor: - Conversion factor relative to L/min unit of measure.
Time base: - Hours, Minutes, or Seconds
Density: - Use density (YES / NO)
Press the (u) [Enter] button, to move the flashing cursor to the digit, which has
to be adjusted. Pressing (p) or (q) will increment or decrement a particular digit
respectively. The numbers will change from 0 to 9 and next to the decimal
16
,
17
point (.). Pressing the (p) button one more time will change the digit on the highlighted position of the cursor back to 0. The same is true in reverse, when pressing the (q) button. Only one decimal point is allowed. If changing position of the
decimal point is required, change decimal point to any desired digit then move the
cursor to the required position and adjust it to the decimal point with (p) or (q)
button. When complete with K-factor value settings, press the (t) [Esc] button to
move in to the Time base settings screen. The following screen will appear:
Figure b-6, User Defined Unit of Measure Screen (Time base)
Use (p) or (q) buttons to highlight desired time base option. Press the (u)
[Enter] button to set the Time base and move in to the Density settings screen.
The following screen will appear:
Figure b-7, User Defined Unit of Measure Screen (Density)
Use (p) or (q) buttons to highlight desired Density option. Press the (u) [Enter]
button when done. The LCD will display the Units of Measure Screen and new settings will be reflected at the bottom status line.
5.3.5 Gas Table Settings
The DFM Mass Flow Meter is capable to store calibration data for up to 10 different gases.
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