RKI Instruments GX-82 - Manual (Page 15)

Model GX-82 Instruction Manual Calibration • 11
Calibrating with the RKI Four-Gas Cylinder
A specially mixed cylinder of gases is available from RKI Instruments that contains the
following mixture:
• 50% LEL methane (CH
4
)
• 12% O
2
• 25 ppm H
2
S
• 50 ppm CO
The RKI Four-Gas Cylinder is ideal for verifying or calibrating all four gas detection
ranges. The ranges can be set individually or all at once, depending upon the type of
calibration cup used.
1. Take the GX-82 to a non-hazardous environment before calibrating.
2. Turn on the GX-82 and allow it to warm-up for five minutes.
3. Adjust the Auto Zero/Span as described in “Normal Operation” on page 6.
4. Use the supplied tubing to connect the calibration cup to the regulator.
5. Attach the calibration cup to the sensor(s).
6. Screw the fixed-flow regulator to the gas cylinder and allow gas to flow into the
calibration cup.
7. Allow adequate time for full response (1 to 2 minutes, or until the readings stabilize).
8. Adjust the COMB SPAN, O
2
ZERO, H
2
S SPAN, or CO SPAN controls as needed, so
the display agrees with the concentrations in the cylinder.
NOTE: When using the RKI Four-Gas Cylinder, adjust the O
2
ZERO control so the
display is 12.0%.
If you cannot set a reading to agree with the calibrating gas sample, replace the
applicable sensor.