Detcon 1000 - Manual (Page 8)

Mdl 1000 H2S E-Chem / Inst. Air
Model 1000 H2S E-Chem w Instrument Air Rev. 1.1 Page 4 of 28
1.5 Interference Data
DM-624 series electrochemical H
2
S sensors are subject to interference from other gases. This interaction is
shown in the following table as the relation between the amount of the interfering gas applied to the sensor,
and the corresponding reading that will occur (in ppm).
Gas
Interference
Carbon monoxide 300ppm ≤1.5ppm
Chlorine 1ppm = -0.2ppm
Ethyl mercaptan 3ppm = 1ppm
Ethylene 100ppm = 0
Hydrogen 1% = < 5ppm
Hydrogen chloride 5ppm = 0
Hydrogen cyanide 10ppm = 0
Nitric oxide 35ppm < 2ppm
Nitrogen dioxide 5ppm = -0.5ppm
Sulfur dioxide 5ppm < 1ppm
Methyl mercaptan 2ppm = 1ppm
1.6 Explosion Proof Enclosures
The sensor is packaged in a cast metal explosion proof enclosure. The enclosure is fitted with a threaded cover
that has a glass lens window. Magnetic program switches located behind the transmitter module faceplate are
activated through the lens window via a hand-held magnetic programming tool allowing non-intrusive
operator interface with the sensor. All calibration and alarm level adjustments can be accomplished without
removing the cover or declassifying the area. Electrical classification is Class I; Div. 1; Groups C, D.
+ +
24VDC OUT
2.1A 18-36 VDC IN
Flow Fault (optional)
Pump/Scrubber
Power Supply/
Terminal PCB
Sensor (side view) Sensor
Right Left
Figure 6 Explosion proof enclosures
A 24VDC power supply and termination PCB for the power, relay contacts, 4-20mA output, and/or RS485
signal, are located in the upper right explosion proof enclosure. The pump and optional low flow fault
assemblies are located in the upper left explosion proof enclosure. Declassify the work area before removing
covers.