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10
Appendices
10.1
Appendix A – Annual Self Calibration Check
It is suggested that users carry out a periodic check to ensure the device is measuring correctly. This would not
be as a replacement to any calibration required for regulatory testing requirements, nor omit the need to
periodic servicing. Such self-calibration check testing can however provide peace of mind and confidence that a
Pulse device and all of its main sensor components are working correctly.
The process is a whole system check whereby the user tests a room or building on a still day with a BTS supplied
“known-opening panel”. If measurements fall within an agreed range, the device is confirmed as functioning
correctly. However, it might be, subject to the nature of use, some trends can be observed e.g. if over the last
year it’s lost 4%, and the limit is 5%, then it fails as it’s trending towards failure and will likely be inaccurate
before the next check. As a basic example of this, a user might expect to observe either a very flat trend line or
worse case, a performance decay trajectory:
Check Date Test Error (%)
01/01/2017
4
01/07/2017
4.4
01/01/2018
4.8
01/07/2018
5.2
01/01/2019
5.6
01/07/2019
6
01/01/2020
6.4
01/07/2020
6.8
01/01/2021
7.2
3
4
5
6
7
8
02/12/2015 01/12/2016 01/12/2017 01/12/2018 01/12/2019 30/11/2020 30/11/2021
Inaccuracy (%) over time
Above: example for illustration only, whereby a customer could use self-calibration checks on their own
equipment where high precision is essential or if there is suspected damage or a fault.
Known Opening Test
This is to be carried out in a room with consistent & known leakage, or a custom-built sheltered test chamber
sited within another building, to remove the need to test on days with less wind.
The “known-opening panel” would include 3 openings with known flowrates at 4Pa. The LPP is then used to
measure the changes in flowrate when each opening (or a combination of 2/3, giving 8 flows) is uncovered,
correctly to within a given range (e.g. 2%).
The known opening panel example:
The panel supplied by BTS is pre-tested in a suitably calibrated lab so that the 4Pa flow rates of each hole are
precisely known. The Pulse customer then executes a test with different combinations of holes covered. This
gives a multi-point check (8 possibilities) which means the testing can happen in any room with background
leakage present, providing that a baseline test is taken before the known opening test panels are opened up.
A
B
C
