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AVL iGEM AMA — Users Guide

5.4.8 ConverterCheck - check of the NOx converter efficiency

The converter installed in the CLD analyzer is used to reduce the NO2 contained in the exhaust gas to NO, which can then be measured in total as NOx. The ConverterCheck is used to test the efficiency of the converter.

Fig. 113 Report COCross Check Page 2

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1 Common test data

2 Overall check status

Information

The ConverterCheck requires a GNU i60 or NGU 4000 converter tester. The GNU i60 and NGU 4000 are connected to Cal in 1 and Cal in 2, respectively.

If the only available converter tester is of a different make, you must perform a manual converter check instead (see ManualConverterCheck - manual NOx converter check (option) on page 195).

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AVL iGEM AMA — Users Guide

5.4.8.1 Parameters

Select the desired Range. Since the check can only be performed within span gas concentration ranges of 27 - 1,000 ppm, you will only be able to select the corresponding ranges here.

Calibration calibrates the analyzer before the check commences.

Purge tube indicates the duration in seconds for which the gas will be acti-vated.

Min. efficiency is the efficiency level in % at which the check is still consid-ered passed.

Max. NO2 in NO specifies the NO2 concentration after the converter in %. This parameter is only adjustable for legislation EPA/ECE.

Span gas concentration indicates the span gas concentrations for the set range.

Automatic ozone generation:

– Waiting period is the period between the time the ozonator is switched on and the measurement. This time is not adjustable.

– Desired NO conc. is the desired NO concentration after the converter in percent and in relation to the span gas. This value is specified by the legislation. The lamp intensity of the converter is set in such a way that this desired NO concentration will be reached.

– The Max. deviation from the desired NO concentration in percent is not adjustable.

Fig. 114 ConverterCheck Parameters

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AVL iGEM AMA — Users Guide

Auto-print automatically prints the report on the default printer when the check is finished.

Reset Check Errors erases all errors that have occurred during the last check. These errors will also be deleted from the alarm window.

Load Default Parameters loads the default settings applying to this check.

5.4.8.2 Performing the check

Test procedure 1. Measurement of NOx and NO undiluted

2. Measurement of NOx and NO undiluted with 10% of synth. air or O2

3. Measurement of NOx and NO with the ozonator lamp switched on

In each case, the NOx channel will be measured first followed by the NO channel.

The efficiency and the NO2 ratio contained in the NO is calculated based on these steps.

The span gas used must be NO with a concentration of 27 - 1,000 ppm. If the

concentration exceeds 500 ppm, the gas must be diluted with O2 in step 2.

Fig. 115 Performing a ConverterCheck

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AVL iGEM AMA — Users Guide

5.4.8.3 Report

1 This section shows the currently running actions, the values measured during the test as well as the result.

2 The errors occurring during the check are shown here.

3 You can enter comments about the test here. Save Comment saves the comments about the test. The remarks are also recorded on the report.

4 Use this section to cancel the check and view the report when the check is complete.

Fig. 116 Report Converter Check

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1 Common test data

2 Analyzer data

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AVL iGEM AMA — Users Guide

5.4.8.4 Formulas

Converter efficiency eff (>90 %):

NO2 portion contained in NO (< set parameter "Max. NO2 in NO"):

5.4.9 ManualConverterCheck - manual NOx converter check (option)

The converter installed in the CLD analyzer is used to reduce the NO2 contained in the exhaust gas to NO, which can then be measured in total as NOx. The ConverterCheck is used to test the efficiency of the converter.

The procedure used for the ManualConverterCheck is basically the same as for the automatic ConverterCheck. The only difference is that the valves and the ozonator used in the converter check must be switched manually by the user.

3 Calibration results if the analyzer was calibrated prior to the check

4 Span gas bottle data

5 Results of the individual steps

6 Test results, individual

7 Test status

A Measured NOx value with ozonator lamp switched on

B Measured value for NOx diluted with synth. air or O2

C Measured value for NO diluted with synth. air or O2

D Measured NO value with ozonator lamp switched on

E Measured NOx value undiluted

F Measured NO value undiluted

Information

The manual converter check can be performed using any converter tester supplying at least 3 l/min of check gas.

The converter tester is connected to the "Cal in 2" inlet. Please note that there is only one quick-connect for the check gases, i. e. if a gas divider has already been connected, the gas connections (NO and O2 or synthetic air) must be disconnected from the gas divider and connected to the converter tester instead.

If a GNU i60 or NGU 4000 converter tester is available, you can also perform an automatic converter check (see ConverterCheck - check of the NOx converter efficiency on page 191).