RKI Instruments GX-2001 Manual - Manual (Page 30)

25 • Calibration Model GX-2001 Operator’s Manual
4. While you are pressing the AIR button, the LCD displays “Hold,” a
prompt for you to keep pressing the AIR button.
5. When the zero readings have been set, the LCD displays “Adj,” which
prompts you to release the AIR button.
Single Calibration
This section tells you how to calibrate the Model GX-2001 using the single
calibration (CAL) menu.
Preparation
Before you calibrate the Model GX-2001, you must set the zero readings
as described in “Setting the Zero Readings for All Target Gasses.” You will
also need the supplies listed below. Calibration kits from RKI Instruments,
Inc. are available for this purpose (see “Parts List”).
• Either a 3-gas or 4-gas calibration cylinder with the following
recommended concentrations:
• 50% LEL methane (CH
4
)
• 12% oxygen
• 50 ppm CO
• 25ppm H
2
S (4-gas cylinder only)
• Balance of nitrogen
• To carry out the calibration, you will need a fixed-flow regulator with a
flow rate of 0.5 LPM (liters per minute), non-absorbent tubing, and a
calibration adapter plate that will fit over the Model GX-2001’s four
sensors.