Download 21209885F

TÜV Rheinland Energie und Umwelt GmbH
Air Pollution Control
Report on the suitability test of the ambient air quality measuring system
Model 5030i SHARP with PM2.5 pre-separator of the company Thermo Fisher
Scientific for the component suspended particulate matter PM2.5,
Report No.: 936/21209885/F
6.1
Page 141 of 424
5.4.8 Tightness of the measuring system
The complete measuring system shall be checked for tightness. Leakage shall not exceed 1 % of the sample volume sucked.
6.2
Equipment
The test required an adapter for tightness check and a mass flow meter.
6.3
Performance of test
The Model 5030i SHARP can perform a tightness check using an adapter.
For testing the leak tightness, the instrument is switched to service mode. First, an external
flow meter is installed at the inlet, followed by a recording of the flow rates indicated on the
instrument itself and by the external measurement as well as of the displayed vacuum (VAC
in mmHg). The instrument flow rate is compared with the flow rate of the external flow meter
and adjusted. Then, the tightness check adapter is inserted into the inlet as connection between inlet and external flow meter. The adapter creates a significantly higher vacuum in the
instrument for it reduces the size of the air sampling opening. The flow rates indicated by the
instrument and by the external flow meter are compared again. Ideally (i.e. at absolute tightness), there should be no difference between both flow rates. The manufacturer specifies a
maximum permissible difference of 0.42 l/min (= 2.5 % of the flow rate). If greater deviations
were to be found, a leak test must be performed taking special care of checking the many fittings above the radiometric measuring head. If the cause cannot be found, the manufacturer
should be contacted.
The tightness check must only be performed with the tightness check adapter and the described procedure. It can otherwise damage the instrument.
It is recommended to check the tightness of the measuring system on a quarterly basis according to the described procedure
6.4
Evaluation
The tightness was checked with the adapter as part of the laboratory test.
The criteria specified by the manufacturer upon which the tightness check is considered
passed – maximum difference of 0.42 l/min (= 2.5 % of the flow rate) between the flow rates
measured by the instrument and by the external flow meter under application of the adapter
– proved to be appropriate parameters for monitoring the instrument’s tightness. The laboratory tests resulted in a maximum leakage < 1 % of the nominal flow rate of 16.67 l/min for
both candidates.
The tightness check must only be performed with the tightness check adapter and the described procedure. It can otherwise damage the instrument.
740300_2013_936_21209885F_EN.docx