What to do if MKS Mass-Flo 1179A Measuring Instruments show no output at zero?
If your MKS Measuring Instruments unit shows no output or overrange at zero after warming up, first check the cable type. If the cable is correct, ensure the valve override function is disconnected. If the issue persists, it may indicate an electronics malfunction, requiring the unit to be returned for service.
Why is my MKS Mass-Flo 1179A Measuring Instruments oscillating?
If your MKS Measuring Instruments exhibit oscillation, it might be due to a controller gain setting that's too high. Try reducing the gain by turning it counter-clockwise. Also, verify that the upstream pressure regulator meets the manufacturer's specifications and that the upstream pressure isn't excessively high. If it is, reduce the upstream pressure.
What to do if MKS Measuring Instruments unit does not achieve full flow?
If your MKS Measuring Instruments unit does not achieve full flow, the upstream pressure might be too low. Try increasing the upstream pressure. Alternatively, excessive valve preload could be the cause.
Why does my MKS Measuring Instruments unit indicate a negative flow?
If your MKS Measuring Instruments unit indicates a negative flow, it is likely that the unit was installed backwards in the gas stream. Reinstall the unit in the proper flow direction.
What to do if MKS Mass-Flo 1179A controller does not function?
If the controller of your MKS Measuring Instruments does not function, this could be due to an electronics malfunction, requiring the unit to be returned for service. Another possibility is a valve sticking.
Essential safety precautions to be followed during all phases of instrument operation.
Essential safety precautions to be followed during all phases of instrument operation.
Precautions for using hazardous materials with the instrument, including purging procedures.
Instructions for connecting gas supply and downstream tubing to the flow controller's inlet and outlet.
Details the pin assignments for the 9-pin Type 'D' connector used with mass flow controllers.
Provides the pinout for the 20-pin Edge Card connector used with mass flow controllers.
Details the pin assignments for the 15-pin Type 'D' connector used with mass flow controllers.
Explains the purpose of Gas Correction Factor (GCF) for accurate flow measurement of different gases.
Provides the formula and parameters for calculating the GCF for pure gases.
Presents the equation for calculating GCF for gas mixtures, including fractional flows and correction factors.
Illustrates GCF calculation for a gas mixture of argon and nitrogen.
Explains the operation of the control valve in the 1179 controller, noting it is normally closed.
Step-by-step guide for starting up the Mass Flow Controller/Meter, including leak testing and power application.
Detailed steps for zeroing the flow controller, ensuring no gas flow is present.
Guidance on adjusting controller gain to reduce flow signal oscillation and improve response.
Explains how to override the control valve to open or close it independently of the set point.
Explains how the controller uses measurement, PID algorithm, and error voltage to control the valve.
Provides instructions for checking and resetting the zero setting for optimal accuracy and repeatability.
Instructs users to contact MKS Sales Offices or Calibration Centers for difficulties or problems.
Presents a chart of common symptoms, their possible causes, and suggested remedies for MFC/MFM issues.
Emphasizes purging with inert gas and using safe gas during valve preload adjustments.
Details steps for powering down, removing the cover, and purging the unit with safe gas.
Reinforces the mandatory use of safe gas during valve adjustments to prevent exposure to hazardous gases.
Instructions on setting gas supply regulator and closing system isolation valves.
Guides on holding the centershaft and loosening the jam nut for adjustment.
Explains how to turn the centershaft while monitoring DMM for target current, with adjustment notes.
Steps for checking valve closed conductance against specification after adjustment.
Details how to find and adjust the current limiting potentiometer R85 on the PC board.
General| Accuracy | ±1% of Full Scale |
|---|---|
| Repeatability | ±0.25% of Full Scale |
| Gas Type | Various (depends on configuration) |
| Response Time | <1 second |
| Operating Temperature | 0 to 50°C |
| Operating Pressure | Up to 150 psig (consult factory for specific pressure requirements) |
| Power Supply | ±15 VDC |
| Output Signal | 0-5 VDC |
| Process Connection | 1/4" |
| Wetted Materials | 316L Stainless Steel |
| Connections | 1/4 inch compression fitting |
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