About; Specifications - Decagon Devices VP-3 Operator's Manual

VP-3
2 About VP-3
Thank you for choosing Decagons VP-3 for measuring vapor pressure,
temperature and relative humidity (RH). This manual is designed to
help you understand the sensors features and how to use this device
successfully. The Decagon VP-3 sensor is an accurate tool for moni-
toring vapor pressure, temperature and relative humidity. The VP-3
utilizes a single sensor chip that measures both temperature and RH.
Each RH/T sensor chip is individually calibrated with temperature
and RH calibrations stored on board and applied before data are out-
put, ensuring best possible accuracy. A micro-processor within the
VP-3 calculates vapor pressure from the RH and temperature mea-
surements and outputs all three parameters using an RS232 (TTL)
string and the common SDI-12 communication protocol.
The VP-3 sensor is packaged in a rugged Delrin housing with the
sensor electronics potted in marine grade polyurethane encapsulant.
The RH/T sensor chip is protected by a hydrophobic porous Teflon
filter that is water and dust proof, but has an extremely high vapor
conductance allowing fast sensor equilibration with the surrounding
atmosphere. An additional stainless steel screen protects the Teflon
filter and RH/T sensor from impact and abrasion. The resulting
ultra-rugged design allows the VP-3 to withstand permanent expo-
sure to hostile conditions, making it ideal for a wide range of appli-
cations including standard meteorological/weather monitoring, evap-
otranspiration measurement, micro-environment monitoring, green-
house monitoring and control, concrete moisture monitoring, and
building humidity monitoring for mold prevention/remediation.
2.1 Specifications
Range: 0 to 100% RH
Resolution: 0.1% RH
Accuracy: Sensor measurement accuracy is variable across a range
of RH. Refer to the chart in Figure 1 to determine the accuracy
Relative Humidity
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2 ABOUT VP-3