Vaisala HMT330WPA Installation Instructions

INSTALLATION INSTRUCTION
HMT330WPA
Warmed Probe Accessory
– Installation kit for mounting of
HMT330 and PTU300 warmed probes
– Designed to hold the a warmed
probe and the additional temperature
probe
– Can be connected to a cable conduit
or supported by a threaded bar
*M211557EN*
© Vaisala 2012. All rights reserved.

OVERVIEW OF HMT330WPA

HMT330WPA is an installation kit for mounting the warmed
probes of the HMT330 and PTU300 transmitters. The kit enables
you to combine the warmed probe and the additional temperature
probe into an easily manageable unit that can be supported by a
cable conduit or a threaded bar. The HMT330WPA should be
installed with the probes pointing down to prevent condensed
water from collecting inside the unit; see Figure 1 below.
Seal upper end of the conduit.
Install thermal insulation if
external environment is in
different temperature than
the measured space.
Point HMT330WPA
downward to prevent
problems with
condensation.
Figure 1 HMT330WPA Recommended Installation
The parts of the HMT330WPA are shown in Figure 2. The screw
sleeve (7) has a PG 16 thread for connecting to a cable conduit.
The flange (9) and the short M3 threaded bars that connect it to
the screw sleeve (8) are only needed when supporting the
HMT330WPA with a threaded bar.
NOTE Before starting, consider how you will
support the finished assembly. If you want to
use a cable conduit, you must insert the
probes through the conduit before
assembling them into the HMT330WPA.
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2
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4
5
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Figure 2 HMT330WPA Parts
1 = Grommet
2 = Measuring tube (T)
3 = Measuring tube (RH)
4 = Support
5 = Tube
6 = Sealing rubber with two-hole cut
7 = Screw sleeve adapter with PG 16 thread for
attaching a cable conduit
8 = M3 threaded bar for connecting the flange (2 pieces)
9 = Flange with M8 thread for threaded bar
For warranty information, visit our Internet pages at:
www.vaisala.com/warranty
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