Analytical Industries GPR-3100 Series Oxygen Purity Analyzer - Manual (Page 24)

Advanced Instruments Inc.
5 Operation
GPR-3100 Rev 2/05 17
Range Selection:
The analyzer display defaults to the sampling mode when 30 seconds elapses without user interface.
The GPR-3100 analyzer provides four (4) standard ranges and gives users a choice of sampling modes.
By accessing the MAIN MENU, users may select either the AUTO SAMPLING (ranging) or MANUAL
SAMPLING (to lock on a single range) mode.
Auto Sampling
The display will shift to the next higher range when the oxygen reading (actually the sensor’s signal
output) exceeds 99.9% of the upper limit of the current range. The display will shift to the next lower
range when the oxygen reading drops to 85% of the upper limit of the next lower range.
For example, if the analyzer is reading 1% on the 0-10% range and an upset occurs, the display will shift
to the 0-25% range when the oxygen reading exceeds 9.9%. Conversely, once the upset condition is
corrected, the display will shift back to the 0-10% range when the oxygen reading drops to 8.5%.
Manual Sampling
The display will not shift automatically. Instead, when the oxygen reading (actually the sensor’s signal
output) exceeds 110% of the upper limit of the current range an OVER RANGE warning will be displayed.
Once the OVER RANGE warning appears the user must advance the analyzer to the next higher range via
the menu and keypad Press MENU, select MANUAL SAMPLING, press ENTER, select the appropriate
MANUAL RANGE and press ENTER again.
Temperature Controlled Heater System with Runaway Protection Circuit
If the analyzer is equipped with an optional temperature controlled heater system, open the front door of
the analyzer to access it. This unit is a PID controller which operates between 0-99
°F. The controller is
programmed to maintain the temperature at 75-85 °F.
Caution: Do not change this setting. A higher temperature setting may drastically reduce sensor life
and possibly cause damage to the electronic circuitry of both the controller and the analyzer.
Warning:
Keep the front door securely fastened closed when the temperature controller is ON.
When power is applied to the temperature controller, the controller tunes itself to eliminate and/or
minimize the over/under shoot of temperature from the set point.
It is recommended that at initial start-up, when replacing the oxygen sensor or when trouble shooting,
turn off the power to the heater or set the temperature set point at 60
°F to turn the heater off to prevent
overheating the analyzer.
This can be achieved by pressing the “INDEX” (LOVE Controller) and then using the UP/DOWN arrow key
to set the temperature to 60
°F. After setting the temperature, press the RETURN key to complete the
process.
With ATHENA controller, simply use the UP/DOWN arrow key to set the temperature to the desired value.
When operating the analyzer under normal conditions, set the temperature between 75-85
°F.
Changing the display value from °F to °C:
1. Push the UP ARROW and ENTER buttons down for 5 seconds to access the SECURE MENU
2. Press INDEX to advance to the F-C MENU
3. Select
°C or °F by pressing the UP ARROW key