General information

Measured components

Maximum of 4, comprising up to 3 infrared-sensitive gases and oxygen

Measuring ranges

2 per measured component

Display

LCD with LED backlighting and contrast control; function keys; 80 characters (4 lines/20 characters)

Operating position

Front wall, vertical

Conformity

CE symbol EN 61000-6-2, EN 61000-6-4

Design, enclosure

Weight

Approximately 10 kg

Degree of protection, 19" rack unit and desktop model

• 7MB2335, 7MB2337 and 7MB2338:
  IP20 according to EN 60529
• 7MB2355, 7MB2357 and 7MB2358:
  IP40 according to EN 60529

Electrical characteristics

EMC interference immunity (electromagnetic compatibility)
Safety extra-low voltage (SELV) with safe isolation

In accordance with standard requirements of NAMUR NE21 (08/98) or EN 50081-1, EN 50082-2

Auxiliary power

100 V AC, +10%/-15%, 50 Hz,

120 V AC, +10%/-15%, 50 Hz,

200 V AC, +10%/-15%, 50 Hz,

230 V AC, +10%/-15%, 50 Hz,

100 V AC, +10%/-15%, 60 Hz,

120 V AC, +10%/-15%, 60 Hz,

230 V AC, +10%/-15%, 60 Hz

Power consumption

Approx. 60 VA

Electrical inputs and outputs

Analog output

Per component, 0/2/4 up to 20 mA, NAMUR, isolated, max. load 750 О©

Relay outputs

8, with changeover contacts, freely configurable, e.g. for measuring range identification;

24 V AC/DC/1 A load, potential-free, non-sparking

Digital inputs

3, dimensioned for 24 V, potential-free

• Pump
• AUTOCAL
• Synchronization

Serial interface

RS 485

AUTOCAL function

Automatic unit calibration with ambient air (depending on measured component),
adjustable cycle time from 0 (1) вЂ¦ 24 hours

Options

Add-on electronics, each with 8 additional digital inputs and relay outputs for e.g. triggering of automatic calibration and for PROFIBUS PA or PROFIBUS DP

Climatic conditions

Permissible ambient temperature

• During operation

5 вЂ¦ 45 °C

• During storage and transportation

-20 вЂ¦ +60 °C

Permissible ambient humidity

< 90% RH (relative humidity) during storage and transportation

Permissible pressure fluctuations

600 вЂ¦ 1 200 hPa

Gas inlet conditions

Sample gas pressure

• Without pump

Unpressurized (< 1 200 hPa, absolute)

• With pump

Depressurized suction mode, set in factory with 2 m hose at sample gas outlet; full-scale value calibration necessary under different venting conditions
(800 ... 1 050 hPa, absolute)

Sample gas flow

72 вЂ¦ 120 l/h (1.2 вЂ¦ 2 l/min)

Sample gas temperature

Min. 0 вЂ¦ max. 50 °C, but above the dew point

Sample gas humidity

< 90% RH (relative humidity), non-condensing

Measuring ranges

See ordering data

Chopper compartment flushing

Upstream pressure approximately 3 000 hPa; purging gas consumption approximately 100 ml/min

Time response

Warm-up period

Approximately 30 min (at room temperature) (the technical specification will be met after 2 hours)

Delayed display (T₉₀ time)

Dependent on length of analyzer chamber, sample gas line and configurable attenuation

Damping (electrical time constant)

Configurable from 0 вЂ¦ 99.9 s

Measuring response

Based on sample gas pressure 1 013 hPa absolute, 1.0 l/min sample gas flow and 25 °C ambient temperature

Output signal fluctuation

< ± 1% of the current measuring range (see rating plate)

Detection limit

1% of the current measuring range

Linearity error

• In the largest possible measuring range:
  < ± 1% of the measuring range full scale value
• In the smallest possible measuring range:
  < ± 2% of the measuring range full scale value

Repeatability

≤ ± 1% of the current measuring range

Drift

Zero point

• With AUTOCAL

Negligible

Full-scale value drift

• With AUTOCAL

Negligible

Influencing variables

Based on sample gas pressure 1 013 hPa absolute, 1.0 l/min sample gas flow and 25 °C ambient temperature

Temperature

Max. 2% of the smallest possible measuring range according to rating plate per 10 K with an AUTOCAL cycle time of 6 h

Atmospheric pressure

< 0.2% of the current measuring range per 1% pressure variation

Auxiliary power

< 0.1% of the current measuring range with a change of ± 10%

Measuring ranges

0 вЂ¦ 5 % to 0 вЂ¦ 25 % O₂, configurable

Service life

Approx. 2 years with 21% O₂

Detection limit

1% of the current measuring range

Time response

Delayed display (T₉₀ time)

Dependent on dead time and configurable attenuation, not > 30 s at approximately 1.2 l/min sample gas flow

Measuring response

Based on sample gas pressure 1 013 hPa absolute, 1.0 l/min sample gas flow and 25 °C ambient temperature

Output signal fluctuation

< ± 0.5% of the current measuring range

Linearity error

< ± 0.2% of the current measuring range

Repeatability

≤ 0.05% O₂

Drift

• With AUTOCAL

Negligible

Influencing variables

Based on sample gas pressure 1 013 hPa absolute, 1.0 l/min sample gas flow and 25 °C ambient temperature

Temperature

< ± 0.5% O₂ per 20 K, relating to a measured value at 20 °C

Atmospheric pressure

< 0.2% of the measured value per 1% pressure variation

Accompanying gases

The oxygen sensor must not be used if the accompanying gas contains the following components: Chlorine or fluorine compounds, heavy metals, aerosols, mercaptans, alkaline components (such as NH₃ in % range)

Typical combustion exhaust gases

Influence: < 0.05% O₂

Humidity

H₂O dew point ≥ 2 °C; the oxygen sensor must not be used with dry sample gases (however, no condensation either)

Measured components

Maximum of 4, comprising up to 2 infrared-sensitive gases, an oxygen component and a hydrogen sulfide component

Measuring ranges

• Smallest measuring range

0 ... 5 vpm

• Largest measuring range

0 ... 50 vpm

Service life of the sensor

Approx. 12 months

Permissible atmospheric pressure

750 ... 1 200 hPa

Permissible operating temperature

5 ... 40 °C (41 ... 104 °F)

Operating mode

• Continuous measurement between 0 and 12.5 vpm
• Discontinuous measurement between 12.5 and 50 vpm

Influencing variables

Accompanying gases

The hydrogen sulfide sensor must not be used if the accompanying gas contains the following components:

• Compounds containing chlorine
• Compounds containing fluorine
• Heavy metals
• Aerosols
• Alkaline components
  (e.g. NH₃ > 5 vpm)

Cross-inferences (interfering gases)

1 360 vpm SO₂ result in a cross-interference of < 20 vpm H₂S

180 vpm NO result in a cross-interference of < 150 vpm H₂S

No cross-interference of CH₄, CO₂ and H₂ (1 000 vpm)

Temperature

< 3% /10 K referred to full-scale value

Atmospheric pressure

< 0.2% of the measured value per 1% pressure variation

Measuring response

Delayed display (T90 time)

< 40 s with sample gas flow of approx. 1 ... 1.2 l/min

Output signal noise

< 2% of smallest measuring range with an attenuation constant of 30 s

Display resolution

< 0.01 vpm H₂S

Output signal resolution

< 1% of smallest measuring range with an attenuation constant of 30 s

Repeatability

< 4% of smallest measuring range

Drift

< 1% of the current measuring range per month

Measured components

Maximum of 4, comprising up to 3 infrared-sensitive gases and an oxygen component

Measuring ranges

2 per component

• Min. 0 ... 2% vol O₂
• Max. 0 ... 100% vol O₂
• Suppressed measuring range possible; e.g. 95 ... 100%

Permissible atmospheric pressure

700 ... 1 200 hPa

Permissible operating temperature

5 ... 45 °C (41 ... 113 °F)

Cross-inferences (interfering gases)

See Table "Cross-sensitivities"

Zero point drift

• Measuring range 2%: max. 0.1% with weekly zero adjustment
• Measuring range 5%: max. 0.1% with weekly zero adjustment
• Measuring range 25% or greater:
  max. 0.5% with monthly zero adjustment

Measured-value drift

Negligible with AUTOCAL

Temperature error

< 2%/10 K referred to measuring range 5%

< 5%/10 K referred to measuring range 2%

Humidity error for N₂ with 90% relative humidity after 30 min

< 0.6% at 50 °C

Atmospheric pressure

< 0.2% of measured value per 1% pressure variation

Delayed display (T90 time)

< 60 s

Output signal noise

< 1% of smallest measuring range

Repeatability

< 1% of the current measuring range