© Vaisala 04/l 2014 This material is subject to copyright protection,
HMT333 Humidity and Temperature Transmitter for Demanding Duct-Mounted
Applications
▪ Vaisala HUMICAP® sensor for superior accuracy and
stability
▪ Graphical display and keypad for convenient operation
▪ Excellent performance in harsh conditions; good chemical
tolerance
▪ Corrosion-resistant NEMA4 housing
▪ NIST traceable calibration (certificate included)
▪ Analog outputs, RS232/485, LAN
▪ MODBUS protocol support (RTU/TCP)
Summary:
▪ Compatible with Vaisala viewLinc software
▪ Humidity parameter options: relative humidity, dew
point/frost point, wet bulb temperature, enthalpy, absolute
humidity, ppm, mixing ratio, vapor pressure, and saturation
vapor pressure
Duct/remote mounted transmitter shall incorporate a thin film polymer capacitive HUMICAP
sensor that is field replaceable and have accuracy of ±1% RH (0…90% RH) and ±1.7% RH (90…100% RH) at
+15 ... +25 °C (59 ... +77 °F). Temperature sensor shall be a platinum 100Ω RTD with a NIST traceable
accuracy of ±0.2°C (0.36°F) at 20°C (68°F). Electronics to be protected in a NEMA-4 enclosure. Transmitter to
be powered by 10…35 VDC, 24 VAC or optional 100…240 VAC and provide two linear selectable analog outputs
of: 4 to 20 mA, 0 to 20 mA, 0 to 1 V, 0 to 5 V, or 0 to 10 V, as well as serial output of standard RS232C (optional
RS 485/422 or Ethernet (LAN)). Transmitter shall also have the option for a third analog output. Remote
probe shall have a measurement range of -40°C to 80°C (-40° to 176°F), or optional -40° to 120°C (-40° to
248°F). Standard cable length to be 2 meters (optional 5 or 10 meters). Additional solar radiation and
precipitation shield for probe can be included if outdoor installation is required. Transmitter shall be
microprocessor based giving the option to calculate and directly output dew point, frostpoint, absolute
humidity, wet bulb temperature, mixing ratio, enthalpy, ppm (volume or weight), partial pressure of water
vapor, and saturation vapor pressure. Transmitter shall also have the option of incorporating a local
graphical/numerical display in its cover. Transmitter shall be able to be calibrated, without disturbing
operation, using a single point electronic transfer standard. NIST traceable calibration certificate included.
Vaisala Model HMT333 Order Guide
®
humidity
1-888-VAISALA (824-7252)
instruments@vaisala.com
www.vaisala.com
with all copyrights retained by Vaisala and its individual partners. All
rights reserved. Any logos and/or product names are trademarks of
Vaisala or its individual partners. All specifications — technical
included — are subject to change without notice.