RKI Instruments HS-94 - Manual (Page 5)

CIRCUIT BOARDS
The GX-82 has two circuit boards; the main board, and the sensor/buzzer board. The
main board contains the electronics and the display. The sensor/buzzer board contains
only the sensor and buzzer, and connects to the main board with a ribbon cable.
OPERATION
1. Start Up
A. Press and hold the POWER switch for two seconds. The buzzer will sound a
single tone, and the display will activate all of its digits and symbols.
B. After about 3 more seconds, the display will show a picture of a battery, and the
current battery voltage. A fully charged battery set will display 3 small blocks in
the battery symbol, and a low battery will display only one or two small blocks.
A dead battery will display no small blocks within the battery symbol.For best
results, replace the batteries when only one small block shows.
C. After another 3 seconds, the display will show the current gas concentration in
the surrounding atmosphere, in either ppm (H2S or CO), or in % volume
(Oxygen). The instrument will sound a double tone to indicate that it is now
warmed up and ready for operation.
2. Verify Operation
To easily verify operation of the OX-94, breathe out over the diffusion sensor on the
top of the instrument. The oxygen reading should drop to about 18%, the audible
alarm for Oxygen deficiency should sound, and the display reading should blink.
Press the POWER / MODE button to reset the alarm.
To verify operation of a toxic sensor on the HS-94 or CO-94, it is necessary to expose
the detector to a concentration of the gas to be detected (H2S or CO). Test gas kits
are available from RKI Instruments, Inc.
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