Flowmeter calibration apparatus
OwnerKatahisa Hirai, Masao Hayakawa +2inventors
InventorsKatahisa Hirai, Masao Hayakawa, Takeshi Yakuwa, Akira Hirai
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Abstract
A heat type mass flowmeter calibration apparatus includes standard heat type mass flowmeters and sonic nozzle type mass flowmeters connected in series. Periodically or when required, the national-standard-traceable sonic nozzle type mass flowmeter that is traceable with respect to a national standard is used to calibrate the standard heat type mass flowmeters. Actual flowmeter measurements are conducted using the calibrated standard heat type mass flowmeter values. Therefore, consistently high precision of calibrations and measurements is guaranteed.
Claims3
A flowmeter calibration apparatus comprising:
- a reference standard heat type mass flowmeter that is used as a practical standard flowmeter for measurements of a test mass flowmeter;
- a sonic nozzle type mass flow rate controller connected in series on a downstream side of the standard heat type mass flowmeter;
- a connection port for effecting a series connection of the test mass flowmeter on the downstream side of the standard heat type mass flowmeter;
- a vacuum pump for maintaining a prescribed ratio between upstream pressure and downstream pressure in the sonic nozzle type mass flow rate controller;
- and
- a control section that includes reference standard flowmeter calibration means that uses the sonic nozzle type mass flow rate controller to effect calibration of the standard heat type mass flowmeter, and a test flow rate measurement means that, based on a result of said calibration, uses the standard heat type mass flowmeter to effect measurement of the test mass flowmeter connected to said connection port.
Dependencies are inferred from the claim text.