Specifications

August 2010
G4500 BLACKBOX PORTABLE OPERATIONAL MANUAL
112
PQZip Recording | Elspec
of any kind. The BLACKBOX Portable device with standard 8GB of internal
memory can record continuously for a duration of several months or even a year
depending on the network pollution level.
Principle of Operation
PQZip compression technology is based on Lossy Compression Method which is
protected under US Federal Patent Law as well as by patent laws in several other
countries.
This figure shows a simplified diagram of the compression/decompression proc-
ess performed with accordance with Elspec PQZip technology.
Voltages and currents are being sensed and scaled to achieve a maxi-
mum resolution using the following A/D process.
The waveforms are being sampled at 1024 samples per cycle resolution
for voltages and 256 samples per cycle resolution for currents.
The resulting digital waveform representation is being passed thru FFT
computation, resulting 512 spectral components (harmonics) per cycle
or voltages and 128 for currents.