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6
Function
If compressed air is not dried before feeding into the compressed air network, considerable
amount of condensate gets accumulated in the air line network and causes malfunctioning of
valves, pneumatic components and finally leads to loss of production. Hence, the pressure
dew point in compressed air system is a decisive parameter for air quality and should be
measured in every plant. In addition, there are applications, where the humid air can lead to
damages, for example, in compressed air lifted shafts or slides.
The pressure dew point instrument TPK 20 is an ideal device for monitoring compressed air
quality and give out an alarm at the right time before any damage occurs. The compact
device is meant for monitoring of cold and membrane dryers up to -20° dtp.
The device is provided with an integrated measuring chamber with protection filter and
diverting throttle and also a plug connection for NW 7.2 mm compressed air socket. The
power supply is through an enclosed plug-in type power supply unit. For installation of
measuring system, no intervention in the compressed air network or electrical fitment work is
required. Alternatively, the measuring system can also be installed in the compressed air
pipeline, to avoid flushing air losses.
7
Functional scope
The device is provided with a display for on-the-spot display of measured dew point values.
The display can be switched between °C and °F units. The selected units are shown on the
display.
Through two potential free relay contacts (Normally open), the alarm signal is passed on to
an alarm unit or a higher level system. Alternatively, the relay contact can also be used for
regulation of dryers.
Two dew point based switching points and switching hysteresis can be adjusted over the soft
touch keyboard. The first switching point can be used, for example, as an early warning
alarm and the second switching point for main alarm. Alternatively, the first switching point
can also be used for regulation of the dryer. The overshooting of second alarm value is
additionally signalled over an LED at the display and also indicated on a acoustic signal
generator.
For connection to a super level regulation or monitoring system, the device has an analog
output 4 ... 20 mA which is scaled on the measuring range of -20 ... +40 °C tpd.
Additionally, a serial interface is also integrated, which enables connection to a PC. Direct
connection to the PC is possible with the RS232/USB connection cable available as
accessories and with this, recording of measurement data is possible. The software PCLOG
available as accessories enables graphic representation of measured values and simplifies
commissioning of larger plants.
The TPK 20 also has a built-in, internal alarm generator as well as an output to connect an
external alarm generator (optical and acoustic). An external alarm light is available as
accessories.