Model 4802A
40
Once the sensor is installed/operating in the field, no attempt should be made to
disconnect the sensor, the conduit of the housing lid without removing power from the
Model 4802A, as such an act would compromise the explosion proof integrity of the field
device.
6.2.3 Splash-Guard & TGA-1
General Monitors produces a universal Splash-Guard, P/N 10395-1, that has been
designed for use on all General Monitors combustible gas and hydrogen sulfide gas
sensors (Figure 66). In addition to the Splash-Guard, a Test Gas Applicator (TGA-1) is
available for delivering a test gas to remotely located sensors, P/N 10460-2.
The Splash-Guard prevents water from rain or equipment wash-downs from being
forced into the sensor cavity and affecting the response of the sensing element.
Constructed of rugged Valox plastic, it has a series of internal baffles to deflect water
down and away from the sensor. This guard (and the TGA-1) is threaded for simple
screw-on installation. The Splash-Guard and TGA-1 are recommended for outside
applications where rain or frequent hose downs occur, such as offshore platforms.
Figure 66 – Splash-Guard Picture
6.2.4 Dust Guard Assembly
The Dust Guard Assembly (Figure 67) is a simple, threaded stainless steel cylinder with
a wire- screen at one end. It is easily removed for cleaning and/or replacement of the
disposable screen.
This General Monitors accessory is specifically designed to prevent dust and particulate
matter from reaching the sensor flame arrestor. Such debris can plug the screen and
limit the amount of gas reaching the active surface of the sensor.
Figure 67 – Dust Guard Picture
