RKI Instruments GX-82A User Manual

Page 32

Model GX-82A Instruction Manual

062796

RKI Instruments, Inc.

3. Bias Current Discharge

The batteries continuously supply a small current to maintain the
toxics sensors, even when the instrument is off (see Sensor
Maintenance). This current drain is minimal, but will result in a
normal discharge of the batteries over a period of several weeks.

Note

If the batteries are fully discharged before replacement,
allow 1/2 hour for the toxic gas circuit to show a normal
response.

Sensor Maintenance

Electrochemical sensors (O

, H

S, CO) gradually deteriorate,

regardless of use, and require periodic replacement. Combustibles
sensor life is generally related to usage, but other factors may affect
duration.

The GX-82A sensors are easy to replace, but only the combustibles
sensor contains user-serviceable components. If a sensor requires
replacement, call RKI or your local distributor. All sensors are
warranted usable for one year from the date of shipment. Sensors that
fail within the warranty period will be replaced at no charge.

Combustibles Sensor

Replace the combustibles sensor or filaments when:

1. The combustibles circuit cannot be calibrated correctly.

2. The HC (%LEL) display does not show 0 immediately after the

start-up sequence, and it cannot be set to zero by the Demand Zero
command.