Vaisala hmdw110 series, Quick Manual

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Introduction to HMDW110 Series
HMDW110 series transmitters are accurate humidity and temperature transmitters for
measurements in HVAC and cleanroom applications. The series consists of the following
models:
• HMD110/112 models for installation in ventilation ducts
• HMW110/112 models for wall installation
• HMS110/112 models for outdoor use
HMDW110 transmitters can be ordered as:
• Loop powered models, with 2-wire current outputs for humidity and temperature
• Separately powered models, with RS-485 Modbus RTU output
HMD112, HMW112, and HMS112 are standard models that are preconfigured for current output at
the factory. HMD110, HMW110, and HMS110 are factory configurable models that are delivered
with customer specific output settings, including calculated humidity parameters and special
scaling of current outputs, or factory activated Modbus RTU functionality.
Loop powered current output models can be connected to Vaisala Remote Display Panel
RDP100 for real-time viewing of the measurements. HMDW110 series can also supply the
operating power to the display using only the loop power from the outputs.
HMDW110 series transmitters offer several output parameters. Relative humidity (RH) and
temperature (T) are the measured parameters, the others are calculated based on RH and T.
Check the type label on your transmitter to verify its output parameters and scaling of the
output channels.
Table 1 HMDW110 Series Output Parameters
Parameter Symbol Units Description
Temperature T °C
°F Temperature in Celsius or Fahrenheit scale.
Relative humidity RH % Ratio of the partial pressure of water vapor in the air to the
saturation vapor pressure of air at current temperature.
Dew point T
d/f
°C
°F Temperature at which the water vapor in the air will
condense into water at the current pressure. When the dew
point is below 0 °C, the transmitter outputs frost point (T
f
)
instead of dew point.
Enthalpy h kJ/kg
BTU/lb Sum of the internal energy of a thermodynamic system.
Wet bulb
temperature T
w
°C
°F The minimum temperature that can be reached by
evaporative cooling in the current conditions.
HMDW110 Series Datasheet and User Guide (in English) are available from the
product page at
www.vaisala.com/hmdw110 .
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