Multimeter settings
To access the multimeter settings, navigate to 'Settings' -> 'Digital Multimeter'. You can adjust settings only if the multimeter was previously paired. If the multimeter is not currently connected, you can connect it using the 'Connect' button. Ensure the multimeter is charged and ready to connect (you may need to wake it up by pressing a button).
"Measurements" tab opens up multimeer digital screen where you can see currently measured values and plot a graph with measured datapoints.
Unpair button will disconnect and unpair active multimeter.
Time synchronization
Time synchronization button only appears when time synchronization mode is selected for capturing ON/OFF potential readings. When time is not synchronized, user cannot use Time sync mode and will be using High/Low mode instead until synchronization is achieved. To request immediate synchronization press the button and wait for the result. In case of GPS synchronization you need to have access to clear sky, in case of NTP - access to the internet.
Cycle Settings
Cycle settings allow you to modify ON/OFF potential cycle durations and select the algorithm used to determine the cycles.
Capture rate
Capture rate indicates how many readings per second multimeter will be capturing. Selecting rate base on the region allows to eliminate AC interference in the captured DC readings.
ON/OFF capture
You can disable ON/OFF capture by deactivating a checkbox. In that case only selected field potential will be captured.
To change the cycle duration, select a token at the top of the screen or manually enter values in the text fields.
Capture modes
There are three algorithms for determining ON/OFF readings during interruption cycle:
High-Low:
Assigns the most negative reading measured during the cycle to the ON potential and the most positive to the OFF potential. Simple and effective but may be inaccurate in case of opposite shifts or false readings collected during the cycle.
Time synchronization
Synchronizes your phone clock with UTC time and records ON and OFF readings according to the current time. Cycle duration must be aliquot to 60 seconds (e.g., 5 sec ON, 1 sec OFF - 6 sec total. 60/6 = 10 cycles per minute).
First cycle - indicates what is the first cycle in the interruption sequence
ON delay and OFF delay - parameters that allow users to adjust the moment of when ON or OFF reading is collected.
Delays are needed adjustment purpose. When UTC time indicates that rectifier was just turned off, it doesn't mean that rectifier is already off and measured reading at that time is your instant off potential. Here are some reasons why:
- Switches take time to change their position.
- DC decouplers in the CP system may smooth ON/OFF transition and therefore instant off reading cannot be measured right away.
- Time synchronization algorithms aren't perfect. The error of synchronization can be as large as 50 ms.
Therefore, you can manually adjust ON/OFF delay parameters, if you see that your ON/OFF readings are captured incorrectly.
Time synchronization method - indicates how time should be synchronized on your phone.
Usually, interrupters are synchronized via GPS and run on the schedule in sync with UTC time. To capture readings at the right moment, your phone time must also be synchronized with UTC. However, unlike interrupters, we can use different methods to achieve this synchronization.
One method is using GPS - same as interrupter, we obtain current time from satellite using phone's GPS module. It requires clear sky access and may take some time to obtain. Another method is NTP (Network Time Protocol). It gathers time data from dedicated time servers. This method doesn't need clear sky view but requires Internet access. You can select either method or use Mixed mode, where phone will use one or another depending on what is available. When synchronization is achieved, "Delta" value is obtained. It indicates the difference between your device internal clock and UTC time, and it is used for determining ON/OFF shifts.
Shift
Determines ON/OFF cycles by analyzing collected readings and cycle duration. Requires different ON and OFF cycle durations for accurate results.