Riken Keiki GD-F3A-SC-A, Operating Manual

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14
６－２．Calibration
Perform gas calibration at new installation, 6 months inspection and sensor replacement.
６－２－１．Required kit and tools for calibration
Prepare following jigs and tools to perform zero and span adjustments.

Calibration adapter

Calibration gas (standard gas for zero and span)

Gas sampling bag for calibration gas

Suction pump to lead calibration gas

Flowmeter with flow control valve (enable to control 1.0L/min).

Ammeter(for measuring 4-20mA)
６－２－２．Performing a zero adjustment
① Plug the ammeter lead into terminals 3 and 5 of terminal strip 2 (No.3 is – and No.5 is +).
② Pack the zero gas (Nitrogen more than 99.9 vol %) into gas sampling bag.
③ Connect calibration adopter, flowmeter （with flow control valve） and suction pump to
the detector head. Turn on the pump and adjust the reading of flowmeter to
1.0±0.3L/min.
④ Connect gas sampling bag for calibration to the IN side of the pump.
⑤ After reading by ammeter gets stable, adjust the reading to 4mA with potentiometer
in ZERO adjusting hole.
⑥ Stop the supply of zero gas, disconnect calibration adapter and confirm that the
oxygen reading returns to 20.9vol% (Completion of zero adjustment).
６－２－３．Performing a span adjustment
① Plug the ammeter lead into terminals 3 and 5 of terminal strip 2(No.3 is – and No.5 is +).
② Pack the span gas (fresh air for oxygen deficiency alarm instrument and their
concentration is around preset alarm level for other purpose) into gas sampling bag.
For simple calibration, you may be possible to use an ambient air as span gas
containing 20.9vol% O2 providing that the ambient pressure is 1 atm (1000±50hpa)
and contamination in air is negligible against span gas concentration.
③
Connect calibration adopter, flowmeter （with flow control valve） and suction pump to
the detector head. Turn on the pump and adjust the reading of flowmeter to
1.0±0.3L/min.
④
Connect gas sampling bag for calibration to the IN side of the pump.
⑤ After reading by ammeter gets stable, adjust the reading to output current
corresponding to the span gas concentration with potentiometer in SPAN adjusting
hole.
⑥ Stop the supply of span gas, disconnect calibration adapter and confirm that the
oxygen reading is 20.9vol % (completion of span calibration).