Aalborg DFC - User Manual

Questions and Answers

B
Becky MartinezAug 13, 2025
How to troubleshoot lack of reading or output in Aalborg DFC?
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  Kevin BakerAug 14, 2025
  If your Aalborg Controller lacks reading or output, several factors could be responsible. First, check the power supply connection. If the fuse (DFC) is blown, disconnect the DFC transducer from the power supply, address the shorting issue or verify polarities; the fuse should reset automatically. Alternatively, if the fuse (SDPROC) is blown, disconnect the power cord, inspect and replace the fuses at the AC power input connector of SDPROC as needed. Other potential causes include a filter screen obstructed at the inlet (flush clean, disassemble, or replace), an occluded sensor tube (flush clean, disassemble, or return to the factory), or a defective PC board (return to the factory for replacement). Finally, incorrect valve adjustment can also be a factor; in this case, readjust the valve.
K
Kyle HansenAug 21, 2025
What to do if Aalborg Controller DFC model has no response to set point?
- S
  Spencer JamesAug 21, 2025
  If your Aalborg Controller (DFC model) isn't responding to the set point, check for the following potential causes: ensure adequate gas pressure is applied. Inspect cables and connections for any malfunctions, replacing as necessary. If the set point is too low (less than 2% of full scale), readjust it. Also, verify that the valve adjustment is correct and readjust if needed.
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Bradley ArmstrongAug 26, 2025
Why doesn't flow reading coincide with set point on Aalborg Controller DFC model?
- S
  Sarah AnthonyAug 26, 2025
  If the flow reading on your Aalborg Controller (DFC model) doesn't match the set point, it could be due to inadequate gas pressure; ensure you apply the appropriate gas pressure. Another potential cause is a filter screen obstructed at the inlet; in this case, flush clean or disassemble to remove any obstructions or replace it. A ground loop, where signal and power supply commons are different, can also cause this issue.
J
Janet MccallAug 28, 2025
What causes DFC valve to not work in open position on Aalborg Controller?
- S
  Stacy KnightAug 28, 2025
  If the DFC valve on your Aalborg Controller isn't working in the open position, it could be due to several reasons. First, ensure the valve adjustment is correct and readjust if necessary. A defective PC board could also be the cause, requiring a return to the factory for replacement. Check the cable and connectors for any malfunctions, replacing if needed. High differential pressure could also prevent the valve from opening; decrease the pressure to the correct level. Finally, ensure there is sufficient inlet pressure and adjust appropriately.
C
Carl JohnstonSep 1, 2025
Why is there full scale output at no flow condition on Aalborg DFC?
- D
  Daniel BrewerSep 1, 2025
  If your Aalborg Controller shows a full-scale output when there is no flow or when the valve is closed, it could be caused by a defective sensor, requiring a return to the factory for replacement. Alternatively, a gas leak could be the issue, so locate and repair any leaks.
C
Chris TurnerSep 5, 2025
How to fix DFC valve that doesn't work in close position on Aalborg Controller?
- S
  shermangeneSep 5, 2025
  If the DFC valve on your Aalborg Controller isn't working in the closed position, several factors could be responsible. First, ensure the valve adjustment is correct and readjust if necessary. A defective PC board could also be the cause, requiring a return to the factory for replacement. Check the cable and connectors for any malfunctions, replacing if needed. Lastly, the orifice could be obstructed; disassemble to remove any obstructions or return the unit to the factory.
M
Maria HamptonSep 8, 2025
What to do if Aalborg DFC Controller output reads at plus or minus saturation only?
- J
  John ClarkSep 9, 2025
  If the output of your Aalborg Controller reads at (+) or (-) saturation only, it could be due to a blown fuse (DFC). Disconnect the DFC transducer from the power supply, address any shorting conditions or check polarities; the fuse resets automatically. Also REMOVE CAUSE OF SHORT CIRCUIT!
M
mark84Nov 16, 2025
Why is the calibration off on my Aalborg Controller?
- A
  Angela RobbinsNov 16, 2025
  If the calibration of your Aalborg Controller is off, several factors could be responsible. Ensure the gas metered matches the calibration specifications, referring to the K factor tables in APPENDIX 2. A change in gas composition could also cause this issue, so locate and correct it. Other potential causes include a gas leak (return to factory for replacement), a defective PC board (flush clean or disassemble to remove impediments), RFE (flush clean or disassemble to remove impediments or return to factory for replacement), a dirty or occluded sensor tube (flush clean or disassemble to remove impediments or replace), or a filter screen obstructed at the inlet (flush clean or disassemble to remove impediments or replace). Lastly, check for any tilt or changes in the mounting of the transdu...

Summary

Unpacking the DFC Mass Flow Controller

Inspect Package for External Damage

Visually inspect the shipping package for any signs of damage before unpacking the unit.

Unpack the Mass Flow Controller

Carefully unpack the unit, check for concealed damage, and verify contents against the packing list.

Returning Merchandise for Repair

Procedure for returning equipment for service, including obtaining a Return Authorization Number and safety certificate.

Installation

Primary Gas Connections

Guidelines for connecting gas lines, emphasizing clean gases, proper fittings, and flow direction.

Electrical Connections

Details on power supply requirements (+/-15VDC) and connections for analog signal output.

Communication Parameters and Connections

Configuration for RS-232 and RS-485 communication, including baud rate, data bits, and pin assignments.

Principle of Operation

Heat Flux Measurement

Explanation of how heat flux applied to a sensor tube measures gas flow rate via thermal resistance.

Microprocessor Control

How the microprocessor and solenoid valve work together for closed-loop flow control and accuracy.

Specifications

DFC 26;36;46 Mass Flow Controllers

Comprehensive technical data including accuracy, repeatability, pressure/temperature limits, and wetted materials.

CE Compliance

Confirmation of compliance with European EMC standards (EN 55011, EN 55082).

Operating Instructions

Preparation and Warm Up

Steps for proper installation, leak testing, and allowing adequate warm-up time for stable operation.

Flow Signal Output Readings

How to view flow rate readings on panel meters, DMMs, or command modules.

Swamping Condition

Explanation of flow rates exceeding maximum capacity and their effect on readings.

Set Point Reference Signal

Setting desired flow rates using analog voltage (0-5VDC) or current (4-20mA) signals.

Valve OFF Control

Using external signals to control the solenoid valve, allowing the flow to be turned on or off.

Valve Open;Purge

Procedure for forcing the solenoid valve open, typically used for system purging.

Analog Interface Configuration

How to configure analog input/output ranges using jumpers on the analog board.

Maintenance

Introduction

Emphasis on using clean gases, avoiding impediments, and general care to maintain performance.

Flow Path Cleaning

Instructions for cleaning the inlet filter screen and flow paths for DFC 26 and 36/46 models.

Valve Maintenance (DFC)

Information on solenoid valve components, O-rings, and periodic cleaning for corrosive gases.

Calibration Procedures

Flow Calibration

Overview of Aalborg's professional calibration services and NIST traceable calibrations.

Calibration of DFC Mass Flow Controllers

Details on field recalibration, required equipment, and solenoid valve orifice selection for range changes.

Troubleshooting

Common Conditions

Initial checks for common issues like cable connections, leaks, power supply, and pinouts.

Technical Assistance

Contact information for Aalborg's technical support team for assistance with operational issues.

Troubleshooting Guide

A detailed guide listing indications, likely reasons for problems, and recommended remedies.

Calibration Conversions from Reference Gases

K Factor Calculation

Explanation of the K factor and its derivation for converting calibration data between gases.

Warranty

Warranty Terms

Details on the warranty period, coverage, customer responsibilities, and conditions that void the warranty.

Aalborg DFC Specifications

General

Category	Controller
Type	Digital Flow Controller
Input Voltage	24 VDC
Display	LCD
Accuracy	± 1% of Full Scale
Output	4-20 mA
Communication Protocol	RS485
Operating Temperature	0°C to 50°C
Response Time	<1 second
Operating Pressure	Up to 100 PSI
Power Supply	24 VDC
Materials	Stainless Steel

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