The type AIC oxygen meter is a simple, low-cost digital meter for oxygen, suitable for measurement of oxygen concentration using a DL probe. It is a very simple, low cost unit, ideally suited to hobby pottery use. The type AIC oxygen meter has a number of features which make it very attractive.
The meter is supplied with:
The type AIC oxygen meter is priced at $A290 each
Please note that all prices are in Australian Dollars and payment must be in Australian dollars.
Please send official purchase order, specifying delivery address to Australian Oxytrol Systems.
Meters are normally despatched by international air freight, such as FedEx or UPS, with all freight and import costs payable by the recipient.
The AIC Digital Meter for oxygen probe is a simple digital volt meter. It will indicate the mV signal produced by the thermocouple in an oxygen probe. This reading can then be converted to temperature by looking up standard thermocouple tables. The meter will also indicate the mV signal produced by the electrochemical oxygen cell in the probe. The oxygen concentration can then be calculated from the Nernst equation, or estimated from a chart.
Battery
The meter operates with a standard 9V battery. Remove the screw on the battery compartment at the
back of the meter, remove the cover and clip the battery in place.
Check operation
Switch on the meter. The meter will automatically check the battery. Whenever the battery needs replacing,
it will display "BAT". Close the cover and replace the screw.
Plug the cable into the probe head. Plug the probe cable into the meter. The connections may vary, depending on the date of manufacture. Instructions are supplied with each meter.
Select "temperature" on the switch. The meter should indicate 0.0 if the probe is at room temperature. Check the polarity of the connections by warming the probe tip. The meter should then show a small positive voltage.
When the probe is ready to use, connect the probe to the meter. Select the "temperature" position. The meter will display the thermocouple signal from the thermocouple in mV. There is no cold junction ambient temperature compensation in the meter, so the reading must be corrected for room temperature. This can be approximated by measuring room temperature separately then adding the thermocouple voltage corresponding to the room temperature.
Example, for an R-type thermocouple:
Ambient temperature is 25°C and meter indicates probe thermocouple signal 8.5 mV
Thermocouple chart shows 25°C corresponds to 0.14 mV
8.5 mV + 0.14 mV = 8.64 mV, which corresponds to 856°C from chart
Hence probe temperature = 856°C
Thermocouple test
Prolonged exposure (hundreds of hours) to high temperature (over 1500°C) causes evaporation of platinum.
The thermocouple can be tested for open circuit or thinning that may lead to failure.
Swap the positions of the yellow and green wires in the meter. Select "TEST" position. The reading should be less than 0.005. A reading of 1 indicates that the thermocouple is either broken or may soon do so. This test should be done at room temperature.
Check temperature
The minimum operating temperature of a zirconia oxygen cell is 700°C. The temperature must be checked before
any oxygen measurements are made. If a hand-operated puffer is used, check that the flow of reference air
does not affect the temperature. Record the temperature before and after making a measurement of the oxygen signal.
Oxygen measurement - take reading
Select "atmosphere" on the meter. Position 1 limits the display to 1 decimal place and position 2 to 2
decimal places. This may be useful in cases where turbulence in the gas under measurement causes rapid
fluctuations in the oxygen signal. For the best accuracy, use position 3, which displays 3 decimal places.
The meter displays the oxygen probe signal in volts.
Oxygen measurement - calculate concentration
The oxygen concentration can be estimated from the nomograph. For greater accuracy, the oxygen concentration
can be calculated from the measured oxygen voltage and temperature, using the Nernst equation.
Use in pottery
See detailed notes on how to use an AIC meter for improved fuel economy and glaze
control in pottery.
Specifications
Accuracy:
Temperature signal ± 0.1 mV, corresponding to +/-7 deg C (typical) for R-type thermocouple or +/-3 deg C for K-type
oxygen signal ±1 mV on position 3