Vaisala HMT330 - Manual (Page 48)

User's Guide _______________________________________________________________________
46 ___________________________________________________________________ M210566EN-K
HMT337 for High Humidity Applications
The HMT337 is designed for environments where relative humidity is
very high, near saturation. The warmed probe prevents the saturation of
the sensor. An additional temperature probe is also available.
See Appendix A on page 185 for a presentation of the following probe
installation kits for HMT337 with installation examples:
- Duct mounting kit
- Cable gland
- Pressure tight Swagelok connector
- Vaisala's Meteorological Installation Kit
The installation kits are available for both humidity and temperature
probe.
Temperature Probe (Optional)
An additional temperature probe is available to measure the ambient
temperature when the HMT337 (with probe warming) is used. The
additional temperature probe allows you to measure other humidity
quantities apart from dewpoint and mixing ratio. The temperature probe
must be connected to the transmitter at the factory. Do not cut and re-
connect the cable yourself.
You must install the additional temperature probe in the same
measurement environment as the HMT337 probe. Make sure that heat
does not transfer from the warmed probe to the temperature probe. For an
example installation, refer to section Example of Installation Through
Roof on page 191.
HMT338 for Pressurized Pipelines
Due to the sliding fit the HMT338 is easy to install into and remove from
the pressurized process. The probe is especially suitable for the
measurements in pipelines. See section Ball Valve Installation Kit for
HMT338 on page 192.