RKI Instruments HS-94 - Manual (Page 6)

WARNING
If the Instrument does not respond to these verifications, take it to a known
“fresh-air” environment, then follow the zero and calibration procedures in
this manual. Repeat the Verify Operation procedure before using the
Instrument in a potentially hazardous location.
3. Normal Operation
The 94 Series Instrument will continuously monitor the atmosphere, display the O
2
,
H
2
S, or CO concentrations present, and sound alarm if a dangerous level is
encountered.
A. Backlight
The instrument has a display backlight to enable reading in dark areas. The
display backlight can be turned on by pressing the Mode button once, and it will
automatically turn off after 20 seconds. The backlight also automatically comes
on anytime any alarm condition occurs, except for low battery alarm.
B. Checking battery voltage
The battery voltage is displayed when the instrument is first turned on, as
described in section 1. B. above. A single tone will sound and the battery voltage
will show on the display. New alkaline batteries will register approximately 3.0V.
The minimum voltage required for operation is 2.1V. As the batteries get used
up, the small blocks within the larger battery outline on the display disappear as
follows:
2.3 volts or higher All three small blocks are present.
2.2 volts Two small blocks are present, indicating 10 to 20 hours of
battery life left.
2.1 volts Only one small block present, indicating less than 10
hours of operation left. It is recommended that the
batteries be changed when they reach this stage.
2.0 volts or lower No small blocks are present. The large battery outline
will blink off and on, and the instrument will sound a
constant tone alarm indicating that the battery is dead.
The battery voltage is now too low to properly operate
the instrument and the batteries must be replaced before
the instrument can be used.
6