Aalborg AFC User Manual
OPERATING MANUAL
AFM and AFC
MASS FLOW METERS
and CONTROLLERS
Technical Data Sheet No. TD9305M Rev. M
Date of Issue: August 2009
TABLE OF CONTENTS
1. UNPACKING THE AFM/AFC MASS FLOW METER.....................
1.1 Inspect Package for External Damage.........................................
1.2 Unpack the Mass Flow Meter/Controller.......................................
1.3 Returning Merchandise for Repair...............................................
2. INSTALLATION............................................................
2.1 Primary Gas Connections............................................................
2.2 Electrical Connections.................................................................
3. PRINCIPLE OF OPERATION..............................................
4. SPECIFICATIONS...........................................................
4.1 AFM 26/36/46 Mass Flow Meters.................................................
4.2 AFC 26/36/46 Mass Flow Controllers..........................................
4.3 CE Compliance............................................................................
5. OPERATING INSTRUCTIONS.............................................
5.1 Preparation and Warm Up...........................................................
5.2 Flow Signal Output Readings.......................................................
5.3 Swamping Condition...................................................................
5.4 Set Point Reference Signal (AFC)................................................
5.5 TTL, Valve OFF Control (AFC)......................................................
5.6 Valve Test/Purge (AFC)................................................................
6. MAINTENANCE............................................................
6.1 Introduction.................................................................................
6.2 Flow Path Cleaning......................................................................
6.2.1 Restrictor Flow Element (RFE).................................................
6.2.2 AFM 26 and AFC 26 models.....................................................
6.2.3 AFM 36/46 and AFC 36/46 models..........................................
6.2.4 Valve Maintenance (AFC).........................................................
7. CALIBRATION PROCEDURES..............................................
7.1 Flow Calibration..............................................................................
7.2 Calibration of AFM Mass Flow Meters............................................
7.2.1 Connections and Initial Warm Up..........................................
7.2.2 ZERO Adjustment.................................................................
7.2.3 SPAN Adjustment.................................................................
1
1
1
1
2
2
2
4
5
5
6
7
10
10
10
11
11
12
12
13
13
13
13
13
14
14
15
15
16
16
17
17
7.3 Linearity Adjustment......................................................................
7.3.1 Connections and Initial Warm Up...........................................
7.3.2 ZERO Adjustment.................................................................
7.3.3 25% Flow Adjustment.............................................................
7.3.4 50% Flow Adjustment............................................................
7.3.5 75% Flow Adjustment.............................................................
7.3.6 100% Flow Adjustment.......................................................
7.4 Calibration of AFC Mass Flow Controllers......................................
7.4.1 Disable Solenoid Valve.........................................................
7.4.2 Valve Adjustment..................................................................
7.4.3 Full Scale Flow Adjustment...................................................
7.4.4 25% Flow Adjustment...........................................................
7.4.5 50% Flow Adjustment...........................................................
7.4.6 75% Flow Adjustment.........................................................
7.4.7 100% Flow Adjustment..........................................................
8. TROUBLESHOOTING.........................................................
8.1 Common Conditions......................................................................
8.2 Troubleshooting Guide...................................................................
8.3 Technical Assistance...................................................................
9. CALIBRATION CONVERSIONS FROM REFERENCE GASES...........
APPENDIX 1 COMPONENT DIAGRAMS..................................................
APPENDIX 2 GAS FACTOR TABLE ("K" FACTORS)...................................
APPENDIX 3 DIMENSIONAL DRAWINGS................................................
APPENDIX 4 WARRANTY.........................................................................
17
17
18
18
18
18
18
18
18
19
19
19
19
19
19
20
20
21
23
23
24
25
29
33
1
1. UNPACKING THE AFM/AFC MASS FLOW METER
1.1 Inspect Package for External Damage
Your AFM/AFC Mass Flow Meter/Controller 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/Controller
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 Aalborg
if you purchased your Mass Flow Meter/Controller 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
2. INSTALLATION
2.1 Primary Gas Connections
Please note that the AFM/AFC Mass Flow Meter/Controller 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.
Attitude sensitivity of the Mass Flow Meter is +
15F. This means that the gas flow path
of the Flow meter/Controller must be horizontal within those stated limits. Should
there be need for a different orientation of the meter, re calibration may be necessary.
It is also preferable to install the AFM/AFC 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 tubings 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)!
AFM/AFC transducers are supplied with standard 1/4 inch (AFM/AFC 26 and 36)
or 3/8 inch (AFM/AFC 46), 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 AFM/AFC's are checked prior to shipment for
leakage within stated limits. See specifications in this manual.)
2.2 Electrical Connections
AFM/AFC transducers require a +15VDC and -15VDC power supply to operate.
Additionally, a readout panel meter, digital multimeter, or other equivalent device
is required to observe the flow signal. A variable analog 0-5VDC reference input
is required for AFC models. The Aalborg7 SDPROC accessory Command
Modules offer a convenient and compact means to fulfill these needs.
AFM/AFC transducers come with a 15 pin "D" connector. The pin diagram is provided on figure 2-3.
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.
FIGURE 2-1, WIRING DIAGRAM FOR AFM/AFC TRANSDUCERS
FIGURE 2-3, AFM/AFC 15 PIN "D" CONNECTOR CONFIGURATION
3
PIN FUNCTION
1
Chassis Ground
2 Common, Signal Ground For Pin 3
3 0-5 VDC Flow Signal
4 +15 VDC Power Supply
5 (-) 4-20 mA Flow Signal (optional)
6 +7 VDC for Local Set Point
7 (unassigned)
8 TTL Valve Off Control (AFC)
9 Control Set Point Input 0 5 VDC (AFC)
10 Common, Signal Ground for Pin 9
11 Common, Power Supply
12 Valve Test Point/Purge (AFC)
13 (unassigned)
14 -15 VDC Power Supply
15 (+) 4-20 mA Flow Signal (optional)
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 your 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 750mA 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.
Cable length may not exceed 9.5 feet (3 meters).
Use of the AFM/AFC 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, AFC model Mass Flow Controllers incorporate a proportionating
solenoid valve. The closed loop control circuit of the AFC continuously compares
the mass flow output with the selected flow rate. Deviations from the set point are
corrected by compensating valve adjustments, thus maintaining the desired flow
parameters.
4
4. SPECIFICATIONS
FLOW MEDIUM: Please note that AFM26/36/46 Mass Flow Meters and AFC26/36/46
Mass Flow Controllers are designed to work with clean gases only. Never try to meter or
control flow rates of liquids with any AFM's or AFC's.
CALIBRATIONS: Performed at standard conditions [14.7 psia (1.01 bars) and 70
F
F
(21.1
F
C)] unless otherwise requested or stated.
ENVIRONMENTAL (per IEC 664): Installation Level II; Pollution Degree II.
4.1 AFM 26/36/46 Mass Flow Meters
ACCURACY: +
1% of full scale, including linearity for gas temperatures ranging from 59
F
F to 77 FF (15 FC to 25 FC) and pressures of 10 to 60 psia (0.7 to 4.1 bars).
REPEATABILITY: +
0.2% of full scale.
TEMPERATURE COEFFICIENT: 0.1% of full scale/
F
C.
PRESSURE COEFFICIENT: 0.01% of full scale/psi (0.07 bar).
RESPONSE TIME: 300ms time constant; approximately 1 second to within +
2% of set
flow rate for 25% to 100% of full scale flow rate.
GAS PRESSURE: 500 psig (34.5 bars) maximum; optimum pressure is 20 psig (1.4 bars).
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%.
MAXIMUM INTERNAL LEAK: 0.5%FS.
LEAK INTEGRITY: 1 x 10-9sccs He maximum to the outside environment.
ATTITUDE SENSITIVITY: 1% shift for a 90 degree rotation from horizontal to vertical;
standard calibration is in horizontal position.
OUTPUT SIGNALS: Linear 0-5 VDC (2000 Ω minimum load impedance); 4-20 mA
optional (50-500 Ω maximum loop resistance); 20 mV peak to peak max noise.
Contact your distributor or Aalborg7for optional RS232 or IEEE488 interfaces.
TRANSDUCER INPUT POWER: +15 +5% VDC, 80 mA max, 1.2 watts; -15 +5% VDC, 10
mA max, 0.15 watts.
Power inputs are each protected by a 750mA M (medium time-lag) resettable fuse, and a
rectifier diode for polarity protection.
5
WETTED MATERIALS: 316 stainless steel, VITON7 O-rings; BUNA-N7, EPR or KALREZ7
O-rings are optional.
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: 1/4" (AFM 26/AFM 36) or 3/8" (AFM 46) compression fittings standard; 1/8" or 3/8" compression fittings and 1/4" VCR7 fittings are optional.
TRANSDUCER INTERFACE CABLE: Flat cable with male 15-pin "D" connector is standard.
Optional shielded cable is available with male/female 15-pin "D" connector ends. [Cable
length may not exceed 9.5 feet (3 meters)].
4.2 AFC 26/36/46 Mass Flow Controllers
ACCURACY: +
1% of full scale, including linearity for gas temperatures ranging from
59
F
F to 77 FF (15 FC to 25 FC) and pressures of 10 to 60 psia (0.7 to 4.1 bars).
REPEATABILITY: +
0.2% of full scale.
TEMPERATURE COEFFICIENT: 0.1% of full scale/
F
C.
PRESSURE COEFFICIENT: 0.01% of full scale/psi (0.07 bar).
RESPONSE TIME: AFC26: 300ms time constant; approximately 1 second to within
+
2% of set flow rate for 25% to 100% of full scale flow.
AFC36/46: 600ms time constant; approximately 2 seconds to within
+
2% of set flow rate for 25% to 100% of full scale flow.
GAS PRESSURE: 500 psig (34.5 bars) maximum; optimum pressure is 20 psig (1.4
bars); 25 psig (1.7 bars gauge) for AFC 46.
MAXIMUM DIFFERENTIAL PRESSURES: 40 psig (2.61 bars) for AFC 46. 50 psig (3.34
bars) for AFC 26/36. Optimum differential pressure is 25 psid (1.7 bars). See Table IV for
pressure drops associated with various models and flow rates.
GAS AND AMBIENT TEMPERATURE: 41
F
F to 122 FF (5 FC to 50 FC). 14 FF to 122 FF
(-10
F
C to 50 FC) - Dry gases only.
RELATIVE GAS HUMIDITY: up to 70%.
MAXIMUM INTERNAL LEAK: 0.5%FS.
LEAK INTEGRITY: 1 x 10-9sccs He maximum to the outside environment.
ATTITUDE SENSITIVITY: 1% shift for a 90 degree rotation from horizontal to vertical;
standard calibration is in horizontal position.
6
OUTPUT SIGNALS: Linear 0-5 VDC (2000 Ω minimum load impedance); 4-20 mA
optional (50-500 Ω loop resistance); 20 mV peak to peak max noise.
Contact your distributor or Aalborg7 for optional RS232 or IEEE488 interfaces.
COMMAND SIGNAL: 0-5 VDC (200K Ω input impedance).
TRANSDUCER INPUT POWER:
AFC 26: (10 sLit/min max) +15 +
5% VDC, 80 mA max,
1.2 watts max; -15 +5% VDC, 200 mA max; 3 watts max;
AFC 36: (50 sLit/min max) +15 +
5% VDC, 80 mA max,
1.2 watts max; -15 +5% VDC, 600 mA max, 9 watts max.
AFC 46 (100 sLit/min max) +15 +
5% VDC, 80 mA max,
1.2 watts max; -15 +5% VDC, 600 mA max, 9 watts max.
Power inputs are each protected by a 750mA M (medium time-lag) resettable fuse, and a
rectifier diode for polarity protection.
WETTED MATERIALS: 316 stainless steel, 416 stainless steel, VITON7 O-rings;
BUNA-N7, EPR or KALREZ7 O-rings are optional.
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: 1/4" (AFC 26/AFC 36) or 3/8" (AFC 46) compression
fittings standard; 1/8" or 3/8" compression fittings and 1/4" VCR7 fittings are optional.
TRANSDUCER INTERFACE CABLE: Flat cable with female 15-pin "D" connector ends is
standard. Optional shielded cable is available with male/female 15-pin “D” connector
ends. [Cable length may not exceed 9.5 feet (3 meters)].
4.3 CE Compliance
Any model AFM or AFC bearing a CE marking on it, is in compliance with the below stated
test standards currently accepted.
EMC Compliance with 89/336/EEC as amended;
Emission Standard: EN 55011:1991,
Group 1, Class A Immunity Standard: EN 55082 1:1992
7
FLOW RANGES
TABLE I AFM 26 AND AFC 26 LOW FLOW MASS FLOW METER/CONTROLLERS*
TABLE II AFM 36 AND AFC 36 MEDIUM FLOW MASS FLOW METER/CONTROLLERS*
TABLE III AFM 46 AND AFC 46 HIGH FLOW MASS FLOW METER/CONTROLLERS*
* 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.
8
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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