Specification - arup-group/pqm-hellebores GitHub Wiki

ADC

channels                                : 4
resolution                              : 16 bits (15 bits usable)
sample rate                             : 7812.5 Sa/second synchronous all channels

Display

resolution                              : 800 x 480 pixels IPS
control                                 : capacitive touch
update rate                             : up to 70 waveform updates/second, zero blind time
measurements                            : 1 update/second in background

Services

operating system                        : Raspberry Pi OS (32 bit Debian 12 'bookworm')
network                                 : Wifi
software update                         : OTA Github
time service                            : NTP server pool
remote access                           : SSH, VNC
measurement log file                    : 1 update/second, CSV format
file transfer                           : Wifi+SCP, Bluetooth
keyboard                                : Bluetooth

Voltage

peak                                    : 450 V
accuracy                                : ± 1 % of reading
resolution                              : 0.1 V

Current

peak                                    : 20 A
continuous                              : 3 A RMS
accuracy                                : ± 2 % of reading
shunt resistance thermal coefficient    : 50 ppm /degree C
full range resolution                   : 0.010 A
low range resolution                    : 0.001 A

Power, VAR and VA

continuous (230V systems)               : 650 VA
accuracy                                : ± 3 % of reading
resolution                              : 0.1 VA

Earth leakage

peak                                    : 10 mA
accuracy                                : ± 5 % of reading + 0.010 mA
resolution                              : 0.001 mA

Frequency

accuracy                                : ± 0.005 Hz
resolution                              : 0.01 Hz

Power quality

power factor                            : ± 3 % of reading
crest factor                            : ± 2 % of reading
THD(v)                                  : ± 5 % of reading
THD(i)                                  : ± 5 % of reading
Harmonic coefficients                   : ± 3 % (h0 to h11), 5 % (h12 to h23), 20% (h24+) of reading