Conditions On Site; Ambient Temperature; Moisture And Corrosion Protection - HBM CFT Operating Manual

Conditions on site

6 Conditions on site
CFT force transducers are made of stainless materials. The transducer must
still be protected from weather conditions such as rain, snow, ice, and salt
water.
6.1

Ambient temperature

The temperature has very little effect on the output signal. To obtain optimum
measurement results, comply with the nominal (rated) temperature range.
All CFT series sensors are mechanically pre-stressed with the corresponding
parts. The pre-stress force depends on the modulus of elasticity of the materi­
als being used. Since the modulus of elasticity varies with the temperature, the
pre-stress force also varies with the temperature. The sensor forwards this
variation as a measurement signal to the charge amplifier. If you want to per­
form quasi-static measurements (for example adjusting measurement chains),
we recommend bringing the measurement chain to a uniform and constant
temperature.
Please be aware that the drift of a piezoelectric measurement chain may
increase at a higher temperature, as the mobility of the charge carriers rises
with the temperature.
6.2

Moisture and corrosion protection

CFT series force transducers meet the conditions of degree of protection IP65
in accordance with EN 60 529, if a connection cable is connected.
With stainless steel force transducers, please note that acids and all materials
which release ions will also attack stainless steels and their weld seams. Any
resulting corrosion could cause the force transducer to fail. In this case, appro­
priate protective measures must be provided. Force transducers should also
be protected against substances that attack stainless steels.
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A02529_04_YCI_00 HBM: public
CFT