RKI Instruments SD-705EC - Manual (Page 22)

PT2E-1140
(1) Zero adjustment method
① Confirm with a portable gas detector that the atmosphere around the detector and
measuring gas inlet is clean and does not contain any gas.
If any gas exists around the detector and measuring gas inlet, fill high- purity air or
external fresh air into the gas sampling bag(separately available).
Attach the calibration adaptor and sampling bag filled with high-purity air to the sensor
and allow for about 2 minutes.
Then, proceed to zero adjustment.
② To make zero adjustment and span adjustment, enter the maintenance mode.
③ Press SET switch ● in LCD display and confirm the sensor set
potential.
④ Press SET switch● in MEMU
⑤ Zero adjustment mode enters and ZERO light and indication value is flickering.
In this time, there is a case that the indication value is alternated. This is caused by
that the actual value is indicated with cancellation of zero suppression which is
worked in normal measuring mode.
⑥ Confirm that fresh air is introduced and press SET switch●。
ZERO light is changed from flickering to lighting). And indicating that zero point is
adjusted. (ZERO adjustment is completed).
If indication value does not become zero after zero adjustment, check the instrument
and piping, and make zero adjustment again. But it cannot be still adjusted zero, gas
sensor has trouble. Put the power off. And consult with our nearest agent.
(2) Span adjustment
Be sure to adjust span after completion of zero adjustment.
Recommend to contact with our authorized agent for span adjustment, as it
requires exclusive jigs.
＊ REMARKS
① Prepare about 5L of calibration gas whose concentration has been confirmed
beforehand(the appropriate concentration is around 1.6times of preset alarm level).
② Make cover the sensor with calibration adaptor and fix it with knurling screw.
③ Connect gas sampling bag prepared in step ① to IN side of calibration adaptor,
flowmeter with flow control value and pump exhaust bag to OUT side respectively as
shown in next figure.
④ Press SET switch● in MENU display 2.5Pn .
When span adjustment mode is entered, SPAN light and indication value on LCD are
flickering.
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