System components D-RX 250

Probe

The probe consists of the probe measuring rod and the measured value processing by the electronics in the measuring head. The probe measuring rod is a probe section that protrudes into the dust duct and is fastened with a flange in the duct. The probe measuring rod is insulated in design because of the triboelectric measurement and has two chambers for differential pressure measurement. The two chambers for pressure measurement are connected to a differential pressure transmitter. One of the two chambers is also connected to the absolute pressure transducer in the transmitter. The gas temperature is measured via a measurement resistance in a third chamber in the center of the probe section. The electronic measured value processing is performed in the probe housing. The temperature of the measurement resistance and the triboelectric raw value are determined here. The two raw values of temperature and tribo signal are transferred digitally to the transmitter.

Differential pressure transducer

The differential pressure transducer converts the differential pressure, created by the gas flowing in the probe measuring rod, into a gas velocity variable.

Transmitter

The transmitter provides the supply voltages for the probe and the measuring transducer for absolute pressure and differential pressure, reads in the raw measured values of these modules and transfer the measured values via the RS-485 interface to the evaluation unit. Through the RS-485 interface the transmitter reads the probe values of the triboelectric measured signal and the temperature.

The differential pressure transducer is connected to the transmitter by means of a two-wire cable. The absolute pressure transducer is located inside the transmitter housing. It receives the pressure from the chamber via a special rod.

Control and evaluation unit

The control and evaluation unit reads out the raw measured values from the transmitter. The measured values for normalized dust concentration and normalized volume flow are calculated in the unit.

It is possible to output all analog values via Modbus or 4/20-mA signals and all status signals via isolated contacts.

Measured-value acquisition

In the simplest case a recorder is used to record the measured values and the reference values. The measured values and status signals that are output can also be fed into an emission calculator system for further processing.

Optional:

• Weather protection cover
• Change-over cock for back purging/zero point control
• Automatic cyclical probe back purging for high dust concentrations
• Hastelloy probes for corrosive gases
• Purge air connection at flange