My ADM1000 always reads zero

One question that occasionally comes up is, why does my ADM1000 always read zero? The ADM1000, ADM2000, and ADM3000 all use a transducer to convert the gas flow entering the meter to an analog value. After that it is converted to a digital value for the microprocessor to act upon.

Because it is a positive displacement type meter, meaning it traps a sample of the gas flow in a sealed chamber for a few milliseconds, too high of a flow can cause the transducer to become damaged, still operating, but the reading is generally wildly off, or a major overflow will crack the casing of the transducer rendering it useless. When this happens, the meter will only read zero as there is no signal from the transducer.

The transducer is a reliable yet delicate device; this is because of the meters ability to measure a flow less than 1 mL. If the flow under test is unknown, turn down the regulator or flow controller on the gas supply before connecting the ADM, then connect the meter to the port and set the regulator to the desired flow, as long as it is 1000 mL or less. Mild overflows typically don’t damage the meter, but better safe than sorry.

Having a new transducer installed isn’t very costly; however the meter will have to be re-calibrated.

To view the ADM1000 flowmeter at Agilent’s website use this link http://www.chem.agilent.com/en-US/products/consumables/gasmanagement/adm1000flowmeter/pages/default.aspx

For questions on annual calibration, repairs, and other questions on meter operation, you may contact California Integration Coordinators, Inc. at www.cic-inc.com or call 530-626-6168 and ask for the Calibration Lab.