Analytical Industries GPR-1600 MS Series PPB Oxygen Analyzer - Manual (Page 13)

Advanced Instruments Inc.
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* Refer to analyzer specifications for comparable data on the Pico-Ion UHP and MS oxygen sensors.
Recommendations General:
¾ The interval between SPAN CALIBRATION should not exceed three (3) months.
¾ Always calibrate at the same temperature and pressure of the sample gas stream.
¾ If a ZERO CALIBRATION adjustment is made during initial installation, it is normally not required again until the sample
system connections are modified or a new oxygen sensor is installed. Therefore the DEFAULT ZERO function is
recommended only when performing a ZERO CALIBRATION and during troubleshooting and should not be repeated before
routine subsequent SPAN CALIBRATION.
¾ If a ZERO CALIBRATION adjustment has NOT been made as described above, perform the DEFAULT ZERO and DEFAULT
SPAN functions when troubleshooting an analyzer and before SPAN CALIBRATION.
¾ Caution: Prematurely initiating the SPAN CALIBRATION function before the analyzer reading has stabilized can result in
erroneous readings. This is especially true when installing a new sensor that must adjust to the difference in oxygen
concentrations. It should take about 2 minutes for the sensor to equilibrate in ambient air from storage packaging.
¾ For 'optimum SPAN CALIBRATION accuracy' use a span gas approximating 80% of the full scale range higher range than
the range of interest (normal use) to achieve the effect of “narrowing the error” by moving downscale as illustrated by
Graph A in the Accuracy & Calibration section.
¾ SPAN CALIBRATION with a span gas approximating 5-10% of the full scale range near the expected oxygen concentration
of the sample gas is acceptable but less accurate than ‘optimum SPAN CALIBRATION accuracy’ method recommended – the
method usually depends on the gas available.
¾ SPAN CALIBRATION at the same 5-10% of the full scale range for measurements at the higher end of the range (example:
calibrating an Oxygen Purity Analyzer in air at 20.9% oxygen with the intention of measuring oxygen levels of 50-100%)
results in the effect of “expanding the error” by moving upscale as illustrated by Graph A and Example 1 in the Accuracy &
Calibration section above and is not recommended. Of course the user can always elect at his discretion to accept an
accuracy error of +2-3% of full scale range if no other span gas is available.
Recommendations Air Calibration:
¾ Do not calibrate an analyzer employing the Pico-Ion UHP or MS sensor, or, an oxygen purity sensor with air.
Mounting the Analyzer
The standard GPR-1600MS is designed to be panel mounted and requires a cutout that accommodates the enclosure and 4
mounting bolts. The design also lends itself to 19” rack mounting with an optional bezel or wall mount enclosures as illustrated
below.
Procedure:
1. The GPR-1600MS is designed for panel mounting directly to any flat vertical surface, wall or bulkhead plate with the
appropriate cut out and four ¼” diameter holes for insertion of the mounting studs located on the back side of the front
panel.
2. When mounting the analyzer position it approximately 5 feet off the floor for viewing purposes and allow sufficient room for
access to the terminal connections at the rear of the enclosure.