Getting Started - Pce Instruments Pce-Tds 200 Serie Bedienungsanleitung

6.2

Getting started

6.2.1 Measuring location
The first step of the installation should be to find a suitable place to mount the sensors. This is a
prerequisite for obtaining accurate measurement results. For this, a basic knowledge of the
pipelines / the piping system is necessary.
Therefore, an infinitely long, straight pipe would be the ideal position. The liquid should not have
any air pockets or impurities. The piping can be vertical or horizontal. To avoid inaccuracies due
to turbulence in the liquid, a straight flow-calming section should be considered upstream and
downstream of the measuring location. Generally speaking, the length upstream of the measuring
location should be at least 10 x the pipe diameter and downstream of the measuring location 5 x
the pipe diameter.
The following chart shows some examples of good positions:
Pipe routings and sensor position
6.2.2 Sensor installation
The PCE-TDS 200 has piezoelectric sensors which can transmit and also receive ultrasonic
waves. The time the ultrasonic waves take to pass through the pipe walls and the liquid allows
conclusions about the flow velocity. Since the transit time of the ultrasonic pulses is very short,
the sensors should be installed as precisely as possible to ensure highest system accuracy.
Take the following steps to install the sensors:
(1) Some pipes have a liner. There can be a boundary layer between the outer diameter of the
pipe and the inner liner. This boundary layer can divert or weaken the ultrasonic waves. In
this case, a measurement will be very difficult.
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Upstream Downstream
L x ø L x ø
up dn
10D 5D
10D 5D
10D 5D
12D 5D
20D 5D
20D 5D
30D 5D