KM 2000 CnHm EM

Hydrocarbon Analyser

Application

The modular constructed ADOS KM 2000 CnHm EM equipment incorporates a microcontroller-aided measurement device for measuring solvents. All combustible gaseous CnHm compounds can be measured with the exception of chlorinated and sulphur-sublimed hydrocarbons.

The thermocouples used for measurements, in conjunction with applying the principle of heat reaction, offer the following advantages:

High degree of sensitivity
Good accuracy
Negligible drift of zero point
Over-range signals have no effect

Fields of Application

Supervision of industrial processes

KM 2000 CnHm EM:
Measuring the emission of hydrocarbons, according to the German clean-air regulations
KM 2000 CnHm:
Measuring solvent saturation
Measuring the concentration of solvents

Concerning room air (ventilation) monitoring
A warning is issued at very low concentrations of poisonous gas thus preventing any danger to health.

1=	Sampled gas intake
2=	Test gas intake
3=	Prefilter or compensating filter
4=	Sampled gas pump
5=	Flow regulator
6=	Flow-through meter
7=	Flow monitor
8=	Heating coil
9=	Catalyst chamber
10=	Reference measuring point
11=	Measuring point
12=	Reaction chamber
13=	Measuring amplifier
14=	Limit monitor 1-4
15=	Measured value integration
16=	Continuous-line recorder
17=	Concentration indicator
18=	Heater
19=	Temperature Control
20=	Resistance-thermometer
21=	Gas outlet
22=	Inert mass
23=	Catalytic converter

Measurement Principle and Function

Gas measurement system

The sampled gas is drawn in by a pump through a feed pipe (heated if required), to the reaction chamber, via a compensating filter, flow regulator and flow-through meter. The gas is warmed to a constant temperature by means of the heater coil and jacket and finally burned in a solid-matter catalytic converter. The difference in temperature before and after combustion, is used as the measurement signal that is prepared and evaluated by the microcontroller-aided analyser.

Analyser

The analyser functions on the principle of heat reaction.The difference in temperatures at the reference measuring point and the measuring point, is a directly-dependent variable of the component part of combustible substances in the gas. The reference measuring point is subjected to the heated non-burned gas mixture, whilst the second probe of the thermocouple pile measures the temperature of the burned gas. A load-independent current of 0-(4)-20 mA is available for connection to electric test meters, plotters and limit value monitors. An RS 232 or RS 485 interface is incorporated for data communication.
The inclusion of a measured value integration provides the facility of forming the average value of measured quantities, continuously or over a prescribed period of time.

Equipment Construction

The hydrocarbon measuring system ADOS KM 2000 CnHm EM consists of the following 19" rack units:

Reaction chamber with sensor and electronics
Gas suction system with or without constant heating for the feed pipes, with sampled gas pump, flow-through meter, flow regulator, flow monitor and filter.
Microcontroller-aided evaluation unit in 19"-system with application specific standard plug-in Euro-cards
Housing

Accessories

CnHm EM sampling probes heated or unheated
Mounting flanges for removal of heated extraction pipes
Heated extraction pipes
Test gas bottles with pressure reducer
Pollution control computer EUR 196 according to the clean-air regulations
Continuous-line recorder
Air purging system
Compensation of CO cross-sensitivity
Automatic calibration system

Note: tested and approved according to the guidelines of the Clean Air Act in 2002, meets the requirements of QAL 1 according to DIN EN14181

Technical Data

Measurement principle:

Measuring the heat of combustion in a catalytic converter

Measuring ranges:

0 - 50 mg C/m³ TOC up to 0 - 1600 g/m³ TOC

Minimum detection limit:

1 mg C/m³TOC

Cross sensitivity
(50 mg/m³measuring range):

concentration:	max. deviation:
200 mg/m³ SO₂	-10 %
30 mg/m³ NO₂	-2,5 %
300 mg/m³ CO	+108 %
300 mg/m³ NO	+7 %

Output signals:

Current interface 0-(4)-20 mA
max. load 400 ohm; RS 232

Response time (t₉₀):

< 200 sec. sampling pipe (approx. 11 m; dead time 10 sec.)

Accuracy:

< 2 % full-scale error

Permissible ambient temperature:

+5 °C to +40 °C

Temperature dependency:

< 5 % full-scale error

Sampled gas flow:

125 l / h (±10 l/h)

Preheating time:

approx. 120 min.

Maintenance interval:

4 weeks with auto-calibration
1 week without auto-calibration

Mains supply:

230 V / 50 Hz; 150 V / 60 Hz; 600 VA

Dimensions (W x H x D):

600 x 478 x 500 mm

Weight:

approx. 43 kg

Test certificate:

TÜV approval according to the clean-air regulations ("TA-Luft");
TÜV-report: 936 / 21 200 245