Riken Keiki GD-3EC, Technical Manual

Page: 154 / 177

10. Product Specifications 10-3 Detection target gases for individual detection principles
154 / 168
10-3 Detection target gases for individual detection principles
10-3-1 Non-dispersive infrared absorption type (Infrared type)
Sensor model Gas name
Gas
symbol
F.S. 1 digit
First
Alarm
setpoint
Second
Alarm
setpoint
Calibration
gas
Operating
temperature
range
Operating
humidity
range
Years of
warranty
IRF-1301* Methane CH
4
100 %LEL 0.5 %LEL 25 %LEL 50 %LEL CH
4
−40 °C -
70 °C
95 %RH or
less
(no conden-
sation)
3 years
IRF-1303* Isobutane i-C
4
H
10
100 %LEL 0.5 %LEL 25 %LEL 50 %LEL i-C
4
H
10
IRF-1315* Propane C
3
H
8
100 %LEL 0.5 %LEL 25 %LEL 50 %LEL
C
3
H
8
i-C
4
H
10
IRF-1435 Carbon dioxide CO
2
2,000 ppm 1 ppm 1,000 ppm - CO
2
IRF-1436 Carbon dioxide CO
2
5,000 ppm 10 ppm 1,000 ppm - CO
2
IRF-1433 Carbon dioxide CO
2
10,000 ppm 10 ppm 1,000 ppm - CO
2
IRF-1437 Carbon dioxide CO
2
2 vol% 0.005 vol% 1 vol% - CO
2
IRF-1438 Carbon dioxide CO
2
5 vol% 0.010 vol% 1 vol% - CO
2
IRF-1439 Carbon dioxide CO
2
10 vol% 0.01 vol% 1 vol% - CO
2
IRF-1334* Methane CH
4
100 vol% 0.5 vol% 25 vol% 50 vol% CH
4
IRF-1316* Ethylene C
2
H
4
100 %LEL 0.5 %LEL 25 %LEL 50 %LEL
C
2
H
4
CH
4
IRF-1340* Isobutylene i-C
4
H
8
100 %LEL 0.5 %LEL 25 %LEL 50 %LEL
i-C
4
H
8
i-C
4
H
10
IRF-1308* n-hexane n-C
6
H
14
100 %LEL 0.5 %LEL 25 %LEL 50 %LEL
n-C
6
H
14
i-C
4
H
10
IRF-1332* Butadiene C
4
H
6
100 %LEL 0.5 %LEL 25 %LEL 50 %LEL
C
4
H
6
CH
4
*Interference occurs due to other hydrocarbon gases.
NOTE
 Install in a location with stable conditions within the specified operating temperature range and free of
sudden fluctuations.
 When calibrating, allow the product to warm up for at least 10 minutes before performing zero calibration
and span adjustment.
 Make sure temperature, humidity, and pressure conditions in the calibration environment are the same as
for the measurement environment. (The reading may fluctuate due to temperature, humidity, and
pressure characteristics and in some cases may exceed the zero suppression value due to sensor
characteristics.)
 For ethylene or butadiene to which the product has low gas sensitivity, set the alarm setpoint to 25 %LEL
or higher.
 Due to infrared absorption characteristics, readings may differ even for the same target gas concentration
if the base gas composition differs significantly between calibration and measurement—for example, if an
air base is used for calibration and a CO
2
base is used for measurement.

Perform maintenance if a warning appears while the life assessment or self-diagnostic function is active.
 Regardless of the detection target gas, the warranty period for IRF sensors is 3 years.