The PMA1170 Analog Humidity Probe is an accurate smart probe for measuring relative humidity and ambient temperature. A memory chip is embedded into the probe to store the signal processing and unit conversion program for the probe

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U.S.Pat.5,946,641

U.S.Pat.5,790,432

FEATURES

• Wide temperature & humidity range
• Instantaneous Dewpoint reading
• High accuracy
• Excellent long term stability
• Selectable units
• Fast response
• Interchangeable sensor
  

APPLICATIONS

• Flat spectral response measurements
• Control of ovens
• Demonstration
• Reference measurements
• IR applications
  

The relative humidity is the ratio of the actual vapor pressure to the saturation vapor pressure at the air temperature, expressed in percent. Relative humidity displays an inverse relationship with absolute temperature when the vapor pressure is held constant.

The Dewpoint calculating program is also included in the memory capsule. The Dewpoint is the temperature the air would have if it were cooled , at constant pressure and water vapor content, until saturation (or condensation) occurred.

A temperature compensated capacitive sensor is used in the PMA1170 Humidity Probe to achieve high accuracy and long term stability over a broad range of environmental conditions. The Humidity probe exhibits low hysteresis. A membrane filter and housing protect the sensor from contaminants. The humidity sensitive capacitive elements for this probe are manufactured to very tight specifications and factory-calibrated
allowing simple replacement, should the sensor get damaged. No additional calibration is necessary.

Humidity is a very important factor for the comfort of humans and animals, operating sensitive electronic equipment, working with high voltage or static sensitive components. Fabrics, adhesives and paper change their properties with the ambient humidity. Even some precision mechanisms might be affected by humidity. Comfortable room relative humidity at 20-25°C is around 50% RH. It may vary from 38% RH in class-10 clean rooms to 60% RH in hospital operating rooms.

Humidity Probe Specifications

• Humidity range 0 to 100% RH
• Temperature range -10 to +60 °C
• Humidity accuracy ±3% (10 - 90% RH)
• Temperature accuracy ±1°C
• Stability better than 1%/year
• Self heating power less than 100µW
• Display resolution 0.1°F, 0.1°C, 0.1K, 0.1%RH
• Units °F, °C, K for Dewpoint and temp., % for RH
• Diameter 1" handle, 0.5" sensor
• Length 11" with handle
• Weight 10oz
• Cable  5ft (1.5m)
  

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