RKI Instruments GasWatch 2 Manual - Manual (Page 10)

5 • Description GasWatch 2 Operator’s Manual
Case
The GasWatch 2’s sturdy, high-impact plastic case is suitable for use in
many environmental conditions, indoors and out. The unit is dust proof and
weather resistant. The case has two halves, the top case and the bottom
case. They are held together by four screws in the bottom case. The case
is a different color depending on the model. The GW-2C for CO is red, the
GW-2H for H
2
S is orange, and the GW-2X for oxygen is blue.
The digital LCD is visible through the top case. It displays gas
concentrations, battery level, time, and other readings including TWA,
STEL, and peak gas levels. Below the LCD are two black control buttons.
The button on the left is labeled POWER/MODE. The button on the right is
labeled AIR.
To the left of the LCD is the buzzer, which is located inside the unit. To the
right of the LCD is the sensor cap which retains the sensor. Above the LCD
is a frosted lens through which the alarm lights are visible.
A battery cover is located on the bottom case and is held in place by two
screws. The wristband attaches to the bottom case.
Wristband
The GasWatch 2 comes with a wristband as a standard accessory so the
unit may be worn as a watch and allow hands-free gas monitoring. The
wristband is held in place with the same type of spring bars that are used in
a watch. The spring bars are protected by hollow tubes which fit into the
wristband. Optional accessories are available from RKI Instruments, Inc.
that can be used in place of the wristband such as a belt clip.
Sensor Cap/Sensor Cover
The sensor cap snaps onto the right side of the case and retains the
sensor. It also retains the sensor cover which is a round hydrophobic disk
membrane which protects the sensor from dirt and weather. A gasket
installed on the sensor seals against the sensor, sensor cover, and sensor
cap.
Charcoal Filter Disk in GW-2C
The GW-2C includes a charcoal filter disk which is located in a recessed
area of the sensor gasket beneath the sensor cover. The charcoal filter disk
removes gases from the sampled air that will cause a response on the CO
sensor such as H
2
S and certain hydrocarbons. If false or elevated CO
readings are noticed, especially in the presence of H
2
S, change the
charcoal filter disk (see the Maintenance section for instructions).