Testo 635 Data sheet

Compact Pro Series

testo 635

%RH

°F

“H

2

0

NEW!

The working standard for temperature and humidity measurements

°F td

Today’s professional humidity measurements
require a reliable and precise humidity probe.

The internationally patented Testo humidity

probe guarantees accurate and reliable

longterm measurement results everytime.

Its proven reliability has been demonstrated
during many endurance tests under extreme
conditions and in international inter-laboratory
testing. Trust Testo probes to deliver measuring
confidence in the most demanding applications.

Reliable long-term humidity measurement

The duct and indoor air temperature range of -4...+158 °F is
monitored with a compact humidity probe. In addition to
relative humidity, both air temperature and dew-point are also
displayed.

Moisture on ceilings and walls is often the result of building
damage or insufficient ventilation. With the help of testo 635,
the difference between the wall surface temperature and the
calculated dew-point temperature of the room can be
determinded with the cross-band probe. The actual
temperature of the wall surface is displayed in seconds.

The rugged humidity probe is available for measuring
equilibrium moisture at higher temperatures up to +280 °F.
Building moisture as well as material moisture can be
displayed by testo 635 on the basis of equilibrium moisture.
Ten material characteristics curves are programmed in the
testo 635 to help determine equilibrium moisture.

The pressure dew-point probe was developed especially for
monitoring humidity in compressed air lines down -76 °F tpd.
The pressure dew-point is displayed directly on the testo 635
with the pressure dew-point probe.

The right probe for every application

With the new testo 635 you can monitor and
analyze air humidity, material moisture (basis:
equilibrium moisture) and pressure dew-point.

Three precision probes were tested in an extensive inter­laboratory test at the PTB in Berlin, the NIST in the USA, the
French National Institute CETIAT, the Italian National Institute
IMGC, the English National Institute NPL, the Spanish National
Institute INTA, JQA in Japan, KRISS in Korea, NRCCM in Peking
and Testo DKD calibrating laborarory. All test results confirmed
their accuracy statements and long-term stability.

Upper electrode allows moisture to penetrate through to the di­electrical layer and is both condensate and dirt-proof

Di-electrical layer polymer, alters
di-electricity constantly with the
relative humidity

Lower
electrode

Carrier
Ceramic substrate for
mechanical protection

Connections
Special anti-corrosive design

Wireless probes offer many advantages over
traditional cable or integrated probes.
Measurements up to 65 ft. are possible. There
is no risk of damaging or tangling wires or
cables. With the testo 635, up to three wireless
probes can be read and displayed at once for
temperature and humidity measurements. The
optional, easily installed wireless module can be
retrofitted at any time in either 635 model.

Wireless probes offer versatility