Analytical Industries GPR-1000 ATEX Portable Trace PPM Oxygen Analyzer - Manual (Page 19)

19
Manual Span
The user must ascertain that the oxygen reading (actually the sensor’s signal output) has reached a stable value
within the limits entered below before entering the span adjustment. Failure to do so will result in an error.
Entering the span value – follow the menu layout in Appendix A.
Preparation - Required components:
Refer to Installing Span Gas section above.
1. Certified span gas cylinder with an oxygen concentration, balance nitrogen, approximating 80% of the full scale
range above the intended measuring range.
2. Regulator to reduce pressure to between 5 and 30 psig.
3. Flow meter to set the flow between 1-5 SCFH,
4. 2 lengths of 1/8” dia. metal tubing measuring 4-6 ft. in length.
5. Suitable fittings and 1/8” dia. metal tubing to connect the regulator to the flow meter inlet
6. Suitable fitting and 1/8” dia. metal tubing to connect to the flow meter vent
7. 1/8” male NPT to tube adapter fitting to connect the 1/8” dia. metal tubing from the flow meter vent to the
mating male quick disconnect fitting supplied with the GPR-1000.
Procedure:
This procedure assumes a span gas under positive pressure and is recommended for an analyzer without an
optional sampling pump, which if installed downstream of the sensor should be placed in the OFF position and
disconnected so the vent is not restricted during calibration.
To assure an accurate calibration, the temperature and pressure of the span gas must closely approximate the
sample conditions.
For calibration purposes, use of the AUTO SAMPLE mode is recommended. However, the user can select the full
scale MANUAL SAMPLE RANGE for calibration as dictated by the accuracy of the analysis required – for example, a
span gas with an 80 ppm oxygen concentration with the balance nitrogen would dictate the use of the 0-100 ppm
full scale range for calibration and a 0-10 ppm measuring range. Select as described above.
1. Access the MAIN MENU by pressing the MENU key.
2. Advance the reverse shade cursor to highlight AUTO SAMPLE.
3. Press the ENTER key to select the highlighted menu option.
4. The following displays appear:
MAIN MENU
AUTO SAMPLE
MANUAL SAMPLE
SPAN CALIBRATE
ZERO CALIBRATE
DEFAULT SPAN
DEFAULT ZERO
>>> 00.00 PPM
AUTO SAMPLING
10 PPM RANGE
24.5 C