6
2-2.
Reference gas calibration
The reference gas calibration means the adjustment method of the reading to actual
concentration (reference gas concentration) by supplying reference/substitute gas
instead of measuring gas. Generally, the gas to show 0% by volume or 0% LEL is used
as reference gas and this is the same meaning of zero adjustment. Make reference gas
calibration from time to time.
Reference gas calibration is done with following procedures.
・Supply reference gas to both GAS IN and GAS OUT by changing the position of
3-way cock etc. which is installed outside.
・Wait until the reading gets stable and check that it shows the correct
concentration(Reference gas concentration).
・If reading is different, press ▲mark of REF CAL for about 5 seconds.
・REF CAL light flickers for about 10 seconds and then, shows reference gas
concentrations.
2-3.
Gas alarm action
The FI-800 provides three alarm patterns such as 「H, HH alarm」, 「L, LL alarm」 and
「L.H. alarm」.
Each alarm action has the 1
st
alarm point(AL1) and the 2
nd
alarm point (AL2) which
are activated when below conditions are covered.
The mark X in below table means gas concentrations.
Alarm pattern
1
st
alarm condition
2
nd
alarm condition
H, HH alarm
X ≧ AL1
X ≧ AL2
L, LL alarm
X ≦ AL1
X ≦ AL2
L, H alarm
X ≦ AL1
X ≧AL2
When measuring gas concentration levels meet with the 1
st
alarm condition, relay
contact for outer alarm works and AL1 light flashes.
But measuring gas concentration levels become out of the 1
st
alarm condition, relay
contact for 1
st
alarm is reset and AL1 light turns off automatically (Self-reset).
2
nd
alarm provides same pattern as for 1
st
alarm.
Confirmation method for alarm pattern and alarm preset levels are described in chapter
「3-4 Checking of preset alarm levels」
There is a case to use the reference gas to show 100 vol.% or exception of 0%
depending on the specifications of FI-800.
Confirm relations between 「reference gas」 and 「reference gas concentration」
with 「Specifications for measuring gas」 prepared separately.
＊
NOTE
