Product Overview - HMT140

HMT140 Quick Guide

Document code
English (United States)
Document type
User guide

The Vaisala Wi-Fi Data Logger HMT140 measures relative humidity and temperature using the connected probe and analog signals – RTD, Voltage, Current Loops, and Boolean Contacts. It is powered with 3 × 3.6 Volt batteries, outputs data via wireless transmitter, and comes with or without an optional LCD display.

The HMT140 series of transmission devices supports several different signal measurements. Available channel types are Relative Humidity (RH) and Temperature (T), RTD, Boolean Contact, Voltage, and Current. The channel types are set at the factory during time of order. Other wireless parameters can be changed afterwards using the configuration port and the included software.

The HMT140 is available either with a fixed probe directly attached to the data logger housing or a remote probe with different cable lengths (3/5/10 m (9.8/16.4/32.8 ft)).

The HMT140 is also available with an optional LCD display without backlight. It is typically installed mounted on the wall with up to 4 screws (not included). Duct installation kits are available as accessories. There is a drilling template inside the back cover of this guide to help you position the screws correctly.

For more information on the HMT140 Data Logger, see the HMT140 User Guide (M211488EN), available at