Some Electrocorder Recording Facts

Q1. How does constant sampling work?

A1. The Electrocorder samples the voltage or current input waveforms 16 times per 50Hz or 60Hz cycle, it then averages each cycle over the selected period (1 sec to 60 min). A cycle is 20ms for 50Hz or 16.6ms for 60Hz. Throughout each averaging period, it monitors and records the lowest & highest voltage (and/or current) cycle values and stores these along with date and time in memory.

For example, on a single channel voltage logger (EC-1V),  you want to record voltage over a period of 1 week - you set the Electrocorder EC-1V to have an averaging period of 2 minutes, which actually gives 10 days of logging until the memory is full. The Electrocorder will sample every voltage cycle during the 10 days of logging. During each 2 minute period it calculates the TRMS (true root mean square), Max and Min values.

At the end of the period the TRMS voltage over that preceding 2 minute period is calculated and saved. Also during the preceding 2 minute period it will have also recorded the single lowest voltage cycle value and the single highest voltage value. For example, taking a voltage input, at the start of the 2 minute period the Electrocorder will start sampling every voltage cycle (1, 2 or 3 phases). It looks at each cycle value and compares each to the lowest and highest it has previously seen to that point during this 2 minute period, if the value is lower (say 90V) than the previous lowest (101V) then it will replace the value in the ‘min voltage’ location. Similarly if it is higher (230V) than the previous highest (222V), it will replace the value in the ‘max'.

The Electrocorder will not identify the exact time of the max or min, except that it occurred during this 2 minute period, which does have a date and time! It will record and calculate the average (TRMS) voltage or current over successive 2 minute periods, along with the date and time. So, for each 2 minute period, 3 values will be recorded, (1) Average Voltage (230V), the average of every cycle during the 2 minute period, (2) Minimum Voltage (209V), the lowest cycle voltage and (3) Maximum Voltage (241V), the highest cycle voltage.

Q2. Can it detect spikes?

A2. YES, it will see events of 1 cycle (16/20ms, 60/50Hz) or longer. It will record a single minimum and a single maximum voltage cycle (16/20ms) during each averaging period. If the averaging period were set to 10 seconds, the Electrocorder would sample every cycle 16 times and at the end of each 10 second period, calculate an TRMS average, also during the 10 second period it would record the lowest and highest cycle value seen. Domestic customers do not normally see events less than one cycle!

Q3. Does it measure true RMS voltage?

A3. YES, it samples every 50Hz or 60Hz voltage cycle 16 times and calculates the TRMS value at the end of each averaging period. It can be set to measure to EN50160:1994 (10 minute rolling average). Any averaging period less then 10 minutes is exceeding the EN50160 standard!