Model 2280A
9
•
Halides: compounds containing Fluorine, Chlorine, Bromine and Iodine
•
Silicones
(often
contained in greases and aerosols). Silicones do not
chemically attack the sensor. They instead, coat it and therefore reduce or
stop its response to H
2
S.
•
Acid
Vapors
•
Caustic liquids or vapors
The presence of such materials in an area does not preclude the use of a sensor.
The feasibility of using a sensor in such areas must be determined by an analysis of
the specific factors in each application. Consult General Monitors before attempting
any such installation.
Sensors used in these areas usually require more frequent calibration checks than
normal and typically have a shorter life. In many such applications the normal two-
year warranty does not apply.
CAUTION:
General Monitors discourages the painting of sensor assemblies. If the
sensor head is painted-over, gas will not be able to diffuse into the
sensor and many paints contain lead, which can poison a sensor.
2.7 Sensor Installation
The standard sensor assembly consists of a sensor housing (GMI P/N 10252-1) and
sensor (P/N 50445-1, -5, or -9), (Figure 3).
NOTE
: When installing the sensors, be sure to leave enough clearance from the
ground and walls to be able to fit the calibration bottles supplied with the
system onto the sensor head.
The dash (
-
) numbers correspond to full-scale ranges of 0-100 ppm, 0-50 ppm or 0-
20 ppm, respectively. The sensor assembly is recognized safe for United States
National Electric Code Class I, Division 1 and Division 2, Groups B, C, and D
hazardous areas, and is approved by the Canadian Standards Association (CSA).