RKI Instruments HS-94 - Manual (Page 3)

The 94 series instruments are very compact to easily fit in a shirt pocket or on a belt. It
also comes equipped with a lanyard which can be used to hang the instrument from the
users shoulder or to wear around ones neck. The 94 series also comes equipped with a
vinyl carrying case for added protection and durability.
The 94 series is housed in a rugged water resistant plastic housing, and has a touch pad
control panel with two pushbuttons from which all functions can be accessed.
These instruments are easy to adjust and maintain, with user replaceable batteries and
diffusion sensors.
INSTRUMENT TYPE GAS DETECTED RANGE
OX-94 Oxygen 0-40% volume
CO-94 Carbon Monoxide 0-500 ppm
HS-94 Hydrogen Sulfide 0-199.0 ppm
COMPONENTS AND CONTROLS
CASE
The 94 Series has a rigid plastic case that is durable and shock resistant. The sensor is
housed within the case, and faces upward. The display and touch pad control panel are
located on the side of the unit. The carrying case covers the entire unit, except it has a
hole for the sensor to protrude through and is also shaped so that it does not muffle the
audible buzzer sound. The plastic case has a substantial spring loaded clip for easy,
secure attachment to ones shirt pocket or belt.
SENSOR
The sensor is mounted within the plastic case on the top of the instrument. A water
resistant disc covers the sensor area, and is held in place with a rubber cap. This cap and
disc should be left in place for maximum water resistance. The sensor is inside the
instrument and is removable if the instrument is opened. The sensor plugs into sockets
on the PCB, for quick periodic replacement. The sensor principles of operation are as
follows:
3