Retrotec Blower Door - Manual (Page 39)

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©Retrotec Inc. 2015
reading at your test pressure, enter Set Pressure, 50 Pa for example, then press the “@” Key to get results at exactly
50 Pa.
To get an even more accurate result and with the fan still running set the Time Averaging to the same amount of
time taken to Capture the Baseline. Channel B will stay blank while the average is being taken after which the result
will be displayed. If the fan does not continue to run during this step, and the longer Time Averaging is set, then you
must wait until the fan comes up to speed, then wait the time for the Averaging before taking a reading because the
gauge will be averaging for the entire time and will be averaging in values below the test pressure. As a rule of
thumb, always wait double the Time Average setting before taking readings.
On the DM32, tap Channel A to activate the Hold feature so the readings don’t change while you’re writing them
down.
4.12.3. Adjust your test fan using Set Pressure
Warning: using this automated procedure will allow the fan to run up to full speed should a door be opened during
the test, causing damage when it is closed. If in doubt, use the previous method.
With the gauge still set to a Time Averaging of 1 second, enter Set Pressure, 50 Pa for example. Change the Range if
you cannot achieve the test pressure or if no flow reading appears on Channel B. Once you get within 10% of your
desired test pressure, press the “@” Key to get results at exactly 50 Pa and with the fan still running set the Time
Averaging to the same amount of time taken to Capture the Baseline. The display will go blank for that same time
period after which you can read your result off the display and change units without affecting the readings. You can
also HOLD the display, shut the fan down and change units.
4.13 Taking Manual Multi-Point Readings for FanTestic Software
In general, the multi-point test requires that the user collect pressures for a pre-test baseline, collect flows for a set
of target pressures (in one or both pressurize and depressurize directions), and sometimes to collect pressures
afterwards for a post-test baseline. The collected data is entered into software such as FanTestic in order to
generate results from the test which indicate the amount of leakage in the tested enclosure.
Each Standard that users comply with for collecting the data and generating the results have different sets of target
pressures (based on different required maximum and minimum target pressures and number of different targets),
different requirements for the baseline measurements, and different ways of calculating the results.
The method described in this section is recommended to achieve the most accurate and repeatable test results.
Skipping or reducing any of the steps may allow your test results to pass, but this does not mean that an accurate
test has been performed.
In order to produce the most Retrotec has included factory defaults in FanTestic which recommend the number or
baseline and target points for each of its supported standards. Unless these recommendations are followed, tests
will not be repeatable and there will not be enough data to determine what went wrong with a particular test.
Retrotec will not be able to analyze the test and recommend corrections if these recommendations are not
followed.
4.13.1. Decide how many test points to take
Taking an accurate test means that results will be more repeatable. Taking an inaccurate test means that re-tests of
the same enclosure may show very different results. Accurate tests results are achieved with more abundant data,
taken over a longer time interval. The EN13829 standard, for example, requires only 5 induced target pressure
points but this will usually produce non-repeatable results, as the following graphs show.