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You are here: Home / Instrument Maintenance / Pump-Up Chamber will not increase in pressure

Pump-Up Chamber will not increase in pressure

Warning!Important Safety Information
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Problem:

“I am pumping the instrument, but chamber pressure is not increasing.”

1. First thing to check is to make sure you are making complete strokes of the piston.

Ensure the instrument is lifted up until it stops. This will ensure that the piston is traveling below the air intake hole at the bottom of the Compression Tube.

2. If there is pressure but consistent leaking –

check the tutorial on leaking.

3. The Compression Tube might have slid out slightly.

Check the Compression Tube to ensure it is properly seated.

You can accomplish this by following these instructions:

Pump Up Chamber will not increase pressure PMS InstrumentsPump Up Chamber will not increase pressure PMS Instruments

A. Loosen the fitting that holds the Pump-Up tube in place.

Pump Up Chamber will not increase pressure PMS InstrumentsPump Up Chamber will not increase pressure PMS Instruments

B. Check inside fitting to ensure that O-Ring is in place and that this area is free of excessive grease or debris.

Pump Up Chamber will not increase pressure PMS InstrumentsPump Up Chamber will not increase pressure PMS Instruments

C. Check to ensure that both ferrules are in proper sequence and in good working condition.

D. Re-insert Compression Tube – ensure it is pushed completely inside of fitting.

E. Tighten nut to finger tight, then tighten 1/8 turn with a wrench. Over-tightening nut swill damage Compression Tube.

Pump Up Chamber will not increase pressure PMS Instruments

4. Check Piston Cup for proper seating, burs or debris.

Piston Cup should be smooth on outside without major scarring or chipping. If damaged, replace as per tutorial.

5) If you are pumping the instrument and it raises up on it’s own when you release it (does not feel like pressure is staying inside chamber).

It is possible the check valve located inside the chamber is plugged and needs to be cleared or replaced. Check the tutorial on leaking for more information about clearing the check valve.

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More Resources:

  • Instruments
    • Instrument Quick-Connect Couplers
    • Filling the Model 610 internal Portable Tank
    • Filling the Model 615, Model 615D or Model 1515D Internal Tank
    • Filling the Portable Tank
    • Sealing a sample in the Compression Gland Cover
    • Setting the Rate Valve
    • What it should look like when it’s all hooked up
  • Making the Measurements – Plant Moisture Stress
    • Interpreting Data
    • Making the Measurement of the Plant Sample
    • Measuring Leaf Water Potential in Wine Grapes
    • Measuring Stem Water Potential (SWP)
    • Measuring Stem Water Potential in Almond Trees
    • Measuring Stem Water Potential in Prune Trees
    • Measuring Stem Water Potential in Walnut Trees
    • PMS – Meaning and Importance
    • Stress levels, crop tables and information
    • Using a Pressure Chamber with Almond
    • Using a Pressure Chamber with Walnuts
    • Using a Pressure Chamber with wine grapes
    • Using a Pressure Chamber with Prunes
    • What kind of plants can be measured?
    • When to make measurements
  • Accessories to Nitrogen Gas Units
    • Installing the Almond Compression Gland Gasket and Insert
    • Installing the Grass Compression Gland
    • Using the Grass Compression Gland
    • Pressure Regulators: Do I need one?
    • Using the Grass Compression Gland with corn
    • Sealing a sample using inserts, gaskets and tools
    • Standard Sealing System

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