19
４－３．Span calibration
Regular span calibration (over 1 time every 6 months) must be done after long time no use
and/or requiring more accurate measuring.
Span calibration is done in following order Preparation → Zero calibration
→ Span calibration .
(1)
Preparation Prepare absorption tube or zero gas, span gas and gas sampling bag.
Zero gas, span gas and gas sampling bag are optional accessories.
(2)
Zero calibration First of all, make zero calibration.
For zero calibration before span calibration, use absorption tube with absorbent agent.
In order to make span calibration more accurately, it is better to use zero gas.
(3)
Span calibration Secondly, make span calibration. Introduce span gas to gas
sampling bag, make span calibration according to following procedure.
８２０ｐｐｍ
（Gas concentration indication.）
ＨＯＬＤ ＳＰＡＮ ＫＥＹ
Press ＡＶＧ ＳＴ． and ＺＥＲＯ switches
simultaneously for 3 seconds.
ＳＥＴ ＺＥＲＯ ＦＩＬＴＥＲ？
（Connect absorption tube.）
Connect to gas inlet correctly.
Press ＥＮＴＥＲ switch, if OK.
ＳＥＴ ＺＥＲＯ ？
（Start zero calibration.）
Confirm absorption tube is connected firmly.
Press ＥＮＴＥＲ switch after over 1 minute.
Press ＥＳＣ． switch, when cancel.
ＳＥＴＴＩＮＧ ＺＥＲＯ
（Zero calibrating.）
Approx. 3 sec. (Zero calibration failure.)
Indication and action at zero calibration failure. （Refer to 3-1.)
ＦＡＩＬ ＺＥＲＯ
（Return to measuring mode by ＥＳＣ． switch.）
ＺＥＲＯ ＳＥＴ ＯＫ
（Zero calibration end.）
