User's Manual

Currency
The currency in which to display the leak cost estimate can be selected from the available options.
Unit cost
This determines the cost associated with the leak size for leak cost estimation. Depending on the
selected leak unit, this determines how much a leak of size 1 l/min or 1 CFM costs in the selected
currency.
Env. temp.
The environmental temperature affects how the sound from a leak propagates through the air.
Specify the temperature in order to get as accurate a leak estimate as possible. The temperature
can be entered either in °C or °F.
Rel. humidity
The relative humidity of the environment affects how the sound from a leak propagates through the
air. Specify the relative humidity in order to get as accurate a leak estimate as possible.
Leak corr.
The leak size estimation in the NL Camera has been developed based on a large set of different
measured leaks. It might, however, in some cases underestimate the leak size, or in other cases
overestimate the leak size, since the leak size depends on a large amount of different variables. If
the leak size estimate systematically differs from your own observations, you can adjust it by
setting the leak correction (leak corr.) factor. A leak correction less than 1.0 will produce smaller
estimates, while a leak correction larger than 1.0 will produce larger estimates.
Partial discharge detection [option]
The NL Camera detects partial discharges based on the sound they emit. The different filters
available on the NL Camera filter out background noise and concentrates on the high and
ultrasonic frequencies where the sound of partial discharges typically is much stronger than the
background noise.
The NL Camera will automatically determine when a detected sound source is likely to be a partial
discharge. This autodetection works for AC frequencies of 50 and 60 Hz. Manual AC frequency
adjustment is available as an option (see below).
When a possible partial discharge has been detected, its so called PRPD (phase-resolved partial
discharge) pattern will be shown on the top of the screen. By default, the pattern is shown in a
small window. Click on the window to enlarge it. Click once more to make it small again.
For more details on the PRPD pattern and how to interpret it, please see the separate application
note on partial discharge analysis.