D-RX 250 combination probe

The combined probe sensor D-RX 250 is a single rod measurement probe for simultaneous measurement of dust concentration, volume flow, temperature and absolute pressure.

Область применения

By combining four selected measuring functions in a single device it is possible to automatically calculate the pollutant mass flow for the preparation of the emission declaration in addition to monitoring the pollutant dust.

Application areas

Not suitable for use behind electrostatic precipitators

Certifications

Suitability-tested by TÜV Cologne, test report 936/800006/A
Itemized in the list of suitable measuring devices for continuous emission measuring
MCERTS incl. testing according to DIN EN 15267-3

Дизайн

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 floating 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

Функции

Dust concentration

The dust concentration is calculated according to the triboelectric measuring principle. The tribo probe measures the electrical charge of the incident particles.

Volume flow

The measurement of the volume flow is based on the mechanical action principle. The probe has two separate chambers, between which a differential pressure builds up under flow.

Absolute pressure

The absolute pressure in the flue gas is measured by a pressure transmitter in one chamber of the probe.

Temperature

The temperature is measured directly in the center of the flue gas in a separate chamber within the probe with a temperature sensor.

Особенности

Only one probe/installation opening in the exhaust gas duct
Compact design, no moving parts, no consumable parts
Continuous conversion to normalized dust concentration in mg/Nm³ and to normalized volume flow in Nm³/h
LCD display in mg/Nm³, Nm³/h, °C and hPa, one analog output for each measured variable
Parameterization at the control unit without the need of a PC or other tools

Технические данные

Measured variables	Dust concentration Volume flow Pressure Temperature
Measuring ranges	0 ... 10 to 0 ... 500 mg/Nm³ 0 ... 9,999,999 Nm³/h¹⁾ 800 ... 1300 hPa 0 ... 200 °C, optional 0 ... 350 °C
Measuring principle
Dust	Tribo electric
Volume	Differential pressure
Sample gas temperature	Above dew point up to 200 °C, optional up to 350 °C
Sample gas humidity	< 80 %
Sample gas pressure	-200 ... +200 hPa
Channel diameter	0.3 ... 5 m
Ambient temperature	-20 ... +50 °C
Degree of protection	IP65
Measured value outputs	4 x 0/4 ... 20 mA, 500 Ω Modbus RTU (RS-485)
Digital outputs	7 relay outputs, load rating 48 V/0.5 A
Digital inputs	6 floating inputs
Accuracy	< 2% of the measuring range
Detection limit	< 2% of the measuring range
Reference point drift	< 1 % of measuring range / month
Zero point drift	< 1 % of measuring range / month
Auxiliary power	115/230 VAC, 50/60 Hz, 50 VA
Dimensions
Probes	180 x 180 x (340 + probe length) mm
Probe length	250/400/700/1000 mm
Weight
Probe	9.5 kg
Electronics	22 kg
Options
Probe back purging, purge air supply	3 bar
Isolator purging, continuous purge air supply	Approx. 2 m³/h

¹⁾ Flue gas velocity > 5 m/s concentration after gravimetric calibration

Дальнейшая информация

Please consult your Siemens sales partner for information on how to correctly configure and order a D-RX 250 combined probe sensor for a Siemens CEMS project.