Vapor pressure, temperature, barometric pressure and relative humidity sensor

The VP-4 sensor probe is an accurate tool to measure air temperature, relative humidity (RH), vapor pressure, and barometric pressure in soil and in air. A microprocessor within the sensor calculates vapor pressure from the RH and temperature measurements. The sensor uses a sensor chip to measure both air temperature and RH and a secondary chip to measure barometric pressure.

Specifications

General  specifications

• Operating temperature: −40 to 80 ºC

• Measurement time: 300 ms

• Dimensions: 1.96 cm (dia) x 5.4 cm (h)

• Cable length: 5 m

Vapor pressure

• Range: 0 to 47 kPa

• Resolution: 0.001 kPa

Temperature

• Range: −40 to 80 ºC

• Resolution: 0.1 ºC

• Equilibration time: < 400 s

• Long term drift: < 0.04 ºC/year typical

Barometric pressure

• Range: 49 to 109 kPa

• Resolution: 0.01 kPa

• Accuracy: 0.4 kPa

Relative humidity

• Range: 0 to 100% RH

• Resolution: 0.1% RH

• Equilibration time: <40 s

• Hysteresis: <1% RH typical

• Long term drift: <0.5% RH/year typical