For over forty years, GE Inspection and Control Technology’s Alumina Moisture Probes have set the standard for performance and measured values in industrial trace moisture measurement.
In use, the MISP2 series trace water probe is connected by a connecting cable to a GE Inspection and Control Technology hygrometer instrument. Ease of use, wide measuring range and tight calibration stability make this system the preferred choice for industrial trace moisture measurement worldwide. This aluminum oxide probe measures trace to constant moisture content in gases and non-aqueous liquids. It is used in conjunction with the GE Measurement and Control Technologies MISP2 Trace Water Analyzer. Suitable for use in the following industries: petrochemical, natural gas, industrial gases, semiconductor industry, furnace gases/heat treatment, power industry, air dryers, pharmaceutical industry, aerospace, and more.

Gold, aluminum and Al2O3 form a capacitor, with gold and aluminum as the two electrodes of the capacitor and Al2O3 as the capacitor’s medium. When the sample passes through the sensor, the water molecules penetrate the capillary pores of Al2O3 to change the medium of the capacitance, i.e., to change the impedance of the capacitance, and get the electrical signal related to the moisture concentration.

Micro water probe MISP2 probe performance
1. Probe type: aluminum oxide moisture probe
2. Calibration: Each probe is individually computer calibrated against a known moisture content, derived from the National Institute of Standards and Technology (NIST).
3. Dew point/frost point temperature: Full calibration range: 60 º to -110 ºC
Standard: 20 º to -80 ºC, data up to -110 ºC
Ultra-low temperature: -50 º to -110 ºC
Extended High Temperature: 60 º to -80 ºC, data up to -110 ºC
4. Accuracy:
±2 ºC (range -100 ºC to +60 ºC)
±3 ºC (range -110 ºC to -100 ºC)
Reproducibility:
±0.2 ºC (range -100 ºC to +60 ºC)
±0.5 ºC (range -110 ºC to -106 ºC)
5. Probe operating temperature (process environment): -110 ºC to 70 ºC
6. MIS probe electronics module operating temperature: -20 ºC to 60 ºC
7. Storage temperature: 70 ºC max.
8. Operating pressure: 5 µm Hg 5000 psig (limited by selected pressure probe – see pressure probe section for details)
9. Flow rate range:
Gases: from static to a linear velocity of 10,000 cm/s at one atmosphere pressure
Liquids: from static to 10cm/s linear velocity at a density of 1g/cc
10. Response time: Less than 5 seconds for 63% step changes in moisture content increase or decrease.
11. MIS Probe/Analyzer Distance: Maximum recommended length 0.9 km (3000 ft).
12. MIS probe/analyzer cable: unshielded, twisted pair, AWG22

Built-in temperature probe
1. Type: thermistor
2. Operating temperature: -30 ºC to +70 ºC
3. Accuracy: ±0.5 ºC (full range)
4. Response time:
1 second (located in well-stirred oil)
10 seconds (located in the distilled air temperature 63% step change higher or lower)

Built-in pressure probe
1. Type: solid-state/piezoelectric resistance
2. Optional ranges:
30 to 300 psig (2.2 MPa)
50 to 500psig (3.5MPa)
100 to 1000psig (7.0MPa)
300 to 3000psig (20.8MPa)
500 to 5000psig (34.6MPa)
3. Accuracy: ±2°C
4. Pressure Rating: 3 times the available pressure range, up to 7500psig