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Alternate calibration method

Michael Ingraham 2019-10-10 15:45:06 -04:00
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Power-monitoring-calibration.md

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You might need to calibrate your power monitoring device as correct measurements are influenced by hardware and timing differences. You might need to calibrate your power monitoring device as correct measurements are influenced by hardware and timing differences.
## What you need # What you need
- Your power monitoring capable device flashed with Tasmota and configured to a correct module/template that supports power monitoring - Your power monitoring capable device flashed with Tasmota and configured with the correct module/template that supports power monitoring
- Calibrated multimeter (AC capable). - An AC capable **calibrated** multi-meter
- A resistive load device (we use a 60 Watt incandescent light bulb in the example). - A **known** wattage load with a **power factor as close to 1** as possible (e.g., a resistive load) for best results
- Resistive load device is any device which draws a constant amount of power such as an incandescent or halogen light bulb (best choice since their power draw is declared on them). Electric kettle or electric heater can also be used but it is recommended to use a power meter in conjunction since the load *could* vary. A resistive load device is any device which draws a constant amount of power. For example, an incandescent or halogen light bulb (best choice since their power draw is declared on them). An electric kettle, heater, or blow dryer are also options but you will also need a power meter since the power draw *could* vary.
- **Do not** use switch mode driven devices such as LED lamps, computer equipment or inductive/capacitive devices such as motors!
- >*(optional)* Calibrated power meter (aka Kill A Watt).
### Step 1 **Do not** use switch mode driven devices such as LED lamps, computer equipment, or inductive/capacitive devices such as motors!
Connect the light bulb to your device. - > A calibrated power meter (A.K.A. Kill-a-Watt) *(optional)*
>*(optional)* Plug your device into the power meter.
Turn power on and wait a few seconds for the power metering to settle on a stable power reading. # Set up
### Step 2 - Connect the load (e.g., a 60W incandescent light bulb) to your device
Open the web UI to your device in one window and open another window to that same devices Console. >*(optional)* Plug your load into the Kill-a-Watt
### Step 3 - Open two Tasmota web UI browser windows for your power monitoring device:
Verify the **Power** reading in the web UI (optionally with the power meter as well) for the expected 60 W and, if needed, change the power offset with command: - Click on Console in one browser window
- Keep the other on the main page to view the Power telemetry data
- Turn the power on to your device. Be sure to turn the output on so the load is powered on as well
- Wait a few seconds for the readings to stabilize
&nbsp;&nbsp;&nbsp;&nbsp;`PowerSet 60.0`<BR>&nbsp;&nbsp;&nbsp;&nbsp;*If you're using something other than a 60W load, enter the your peripheral's power rating* ## Method 1
### Step 4 1. Verify the **Power** reading in the web UI (optionally with the power meter as well) for the expected wattage. Adjust the power offset if needed (in Watts):
Verify the **Voltage** reading with the multimeter and if needed change the voltage offset in V with command: [`PowerSet 60.0`](Commands#powerset)
_If you're using something other than a 60W bulb, enter your load's power rating_
&nbsp;&nbsp;&nbsp;&nbsp;`VoltageSet <voltage>`<BR>&nbsp;&nbsp;&nbsp;&nbsp;*Replace `<voltage>` with the reading on your multimeter. Your voltage will vary depending on the electrical standards and your electrical grid* 2. Verify the **Voltage** reading with the multi-meter. Adjust the voltage offset if needed (in Volts):
### Step 5 [`VoltageSet <voltage>`](Commands#voltageset)
Verify the **Current** reading by calculating current value (amperage) using formula **P<sub>(W)</sub>/V<sub>(V)</sub>=I<sub>(A)</sub>** and if needed change the current offset in *mA* (mA=A\*1000) with command: _Replace `<voltage>` with the reading on your multi-meter. Your voltage will vary depending on the electrical standards and your electrical grid_
&nbsp;&nbsp;&nbsp;&nbsp;`CurrentSet <current>`<BR>&nbsp;&nbsp;&nbsp;&nbsp;*Replace `<current>` with your calculated value for ***A (multiplied by 1000)**** 3. Verify the **Current** reading by calculating current value (amperage) using this formula: **P<sub>(W)</sub>/V<sub>(V)</sub>=I<sub>(A)</sub>**. Adjust the current offset if needed (in milliAmps (mA=A\*1000)):
### Step 6 [`CurrentSet <current>`](Commands#currentset)
Confirm the validity of your calibration process checking **Power Factor** from the WebUI which should be `1.00` or as close as possible to `1.00`. In theory resistive loads will always provide a **Power Factor** of 1.00. If that is not the case, we recommend you repeat the calibration process and make sure everything was done correctly. _Replace `<current>` with your calculated value (in milliAmps)
Current calculation: `CurrentSet` calculation:
``` P/V=I
P/V=I 1000 * Watts/Volts = milliAmperes
W(atts)/(V)oltage=(A)mperes
watts/volts *1000=CurrentSet value Example: 1000*(60.0/235.5) = 254.777
Example: (60.0/235.5)*1000=254.777 4. Confirm the validity of your calibration process checking `Power Factor` from the web UI which should be as close as possible to `1.00`. In theory resistive loads will always provide a power factor of 1.00. If that is not the case, we recommend you repeat the calibration process and make sure everything was done correctly.
```
### End ### Script for automatic calibration
[Tampermonkey script](https://gist.githubusercontent.com/blakadder/beb92969e5af570dfb34d0001dee4754/raw/44c048dfc925d591f7f1b677c1de738d6489d970/powcalscript) submitted by [@yuuya45](https://github.com/yuuya45)
## Method 2
The [`CurrentCal`](Commands#currentcal), [`PowerCal`](Commands#powercal), and [`VoltageCal`](Commands#voltagecal) commands allow fine tuning of the power calibration.
Repeat the procedure below for each of the three readings: Current, Power, and Voltage using the corresponding calibration command ([`CurrentCal`](Commands#currentcal), [`PowerCal`](Commands#powercal), and [`VoltageCal`](Commands#voltagecal) respectively). **Take note that the offset ranges vary for each command**.
### Procedure
- Check the reading using the multi-meter
- Compare it with the reading on the Tasmota web UI
- If there is an observed difference, change the offset value by issuing the calibration command in the Console (e.g., `PowerCal 10000`)
- Adjust the offset value up or down until the readings on the multi-meter and the web page are as close as possible
# End
Congratulations, your device can now reliably monitor power consumption! Congratulations, your device can now reliably monitor power consumption!
## Script for automatic calibration
[Tampermonkey script](https://gist.githubusercontent.com/blakadder/beb92969e5af570dfb34d0001dee4754/raw/44c048dfc925d591f7f1b677c1de738d6489d970/powcalscript) submitted by [@yuuya45](https://github.com/yuuya45)