Introduction to HMDW110 series - HMD110 - HMD112 - HMS110 - HMS112 - HMW110 - HMW112 - TMD110 - TMW110

Vaisala HUMICAP® Humidity and Temperature Transmitter Series HMDW110 measure relative humidity and temperature in multiple HVAC applications. The series includes transmitters for duct mounting, IP65-rated wall transmitters, immersion temperature transmitters, and outdoor transmitters with integrated radiation shields. The transmitters can be ordered with an optional display or without a display.

The series consists of the following models:

• HMD110/112 models (RH+T) for installation in ventilation ducts

• TMD110 (T) temperature transmitter for duct installation

• HMW110/112 models (RH+T) for wall installation

• TMW110 (T) temperature transmitter for wall installation

• HMS110/112 models (RH+T) for outdoor use

• TMI110 models (T) for measuring heating/cooling water temperatures

The transmitters can be ordered as:

• Loop powered models, with 2-wire current outputs for humidity (when applicable) 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, TMD110, HMW110, TMW110, TMI110, and HMS110 are factory configurable models that are delivered with customer specific output settings, including calculated humidity parameters (when applicable) and special scaling of current outputs, or factory activated Modbus RTU functionality.

HMDW110 series transmitters offer numerous output parameters. The measured parameters are relative humidity (RH) and temperature (T), and the other parameters 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	Td/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 (Tf) instead of dew point.
Enthalpy	h	kJ/kg BTU/lb	Sum of the internal energy of a thermodynamic system.
Wet bulb temperature	Tw	°C °F	The minimum temperature that can be reached by evaporative cooling in the current conditions.