Benefits of the CR-2
- Wide Range: down to -100 °C (15 ppb)
- Fast Response Time: typically 10-20 seconds
- Inherent Stability and Accuracy
- NIST-traceable
- Very Low Maintenance
The CR-2 exhibits the same wide range, fast response and high reliability as the CR-1A, but it is designed specifically for aircraft and similar high-stress applications. Instead of using Liquid Nitrogen (LN2), mirror cooling is accomplished using a tactical cryocooler, which is a high-tech device used primarily to cool IR detectors in missiles and tank turrets to LN2 temperatures.
Maintenance requirements for the CR-2 are minimal. Aside from occasional mirror cleaning, the cryocooler needs to be renewed every 10,000 hours of use. Both the control circuitry and the sensing assembly are mounted together into a single compact unit. A separate display module is provided that displays the dew / frost point and housekeeping signals. (For aircraft operation, the display module is not required.)
The CR-2 include a ±0.1% accuracy pressure transducer, essential in demanding applications for compensating the dew/frost point temperature for minute differences between sample chamber pressure and atmospheric pressure.
CR-2 Hygrometer Specifications
Measurement Range |
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Dew / frost point temperature |
-100 to +30°C |
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Lowest Concentration ppbv |
15 |
Reading Accuracy °C |
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Entire Range |
±0.1°C |
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Concentration |
±2% |
Typical Response Time |
10-20 seconds |
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Operating Range |
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Temperature |
-40 to +60°C |
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Pressure, psia (bar) |
5 to 30 psia (0.3 to 2 bar) |
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Air / Gas flow range |
0.2 to 3 liters/min |
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Altitude |
0 to 25 km |
Cooling Mechanism |
Stirling Cycle Cryocooler |
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Power Requirements |
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Standard |
28 vdc, < 50 W |
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Optional |
115-220 vac, 50-400Hz, < 50 W |
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Outputs |
0-10V, 4-20mA, Alarm, RS-232 |