# Am I using my watt meter correctly? **URL:** \ **Category:** Factual Questions\ **Tags:** tools-electric-diy\ **Created:** [February 16, 2024, 4:38pm UTC](https://boards.straightdope.com/t/am-i-using-my-watt-meter-correctly/997671 "2024-02-16T16:38:26Z")\ **Posts on this page:** 8\ **Page:** 2
**Author:** ![Crafter\_Man](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/crafter_man/32/458_2.png) [@Crafter\_Man](https://boards.straightdope.com/u/Crafter_Man)\ **Post date:** [February 17, 2024, 1:53am UTC](https://boards.straightdope.com/t/am-i-using-my-watt-meter-correctly/997671/21 "2024-02-17T01:53:28Z")
> [@Dr.Strangelove](#): > > that only works for loads that are somewhere on the spectrum of pure inductive and pure resistive, which isn’t always the case (like with many dimmer switches). Agree. As mentioned, the only “good” way to measure power is to use high speed ADCs and perform simultaneous measurements of instantaneous current and instantaneous voltage. Multiply each pair, take an average over a time interval (preferably an integer number of cycles) and then display it on the LCD. It will be real, average power, which is what you want. And with this technique you don’t have to worry about true RMS, phase angles, etc. ---
**Author:** ![markn\_1](https://avatars.discourse-cdn.com/v4/letter/m/f9ae1b/32.png) [@markn\_1](https://boards.straightdope.com/u/markn_1)\ **Post date:** [February 17, 2024, 2:15am UTC](https://boards.straightdope.com/t/am-i-using-my-watt-meter-correctly/997671/22 "2024-02-17T02:15:23Z")
This obviously varies depending on your electricity provider, but mine has a web page that allows you to view your hourly whole-house electric usage. That’s not going to tell you which device is using power, but it’s an easy way to compare total usage across various times, days and seasons. ---
**Author:** ![md-2000](https://avatars.discourse-cdn.com/v4/letter/m/9d8465/32.png) [@md-2000](https://boards.straightdope.com/u/md-2000)\ **Post date:** [February 17, 2024, 2:17am UTC](https://boards.straightdope.com/t/am-i-using-my-watt-meter-correctly/997671/23 "2024-02-17T02:17:00Z")
Most power draws - AC (summer); dryer; electric stove; dishwasher (heat element dry cycle); hot water heater; furnace fan (assuming you don’t use electrical heaters); I would wonder if you had a hot water drip somewhere too…or did a lot more laundry or dishes compared to last year, or took longer showers. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [February 17, 2024, 2:07pm UTC](https://boards.straightdope.com/t/am-i-using-my-watt-meter-correctly/997671/24 "2024-02-17T14:07:22Z")
Surely, the “good” way to measure power is to use the same technique that your electric meter is using, whatever that is. ---
**Author:** ![Crafter\_Man](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/crafter_man/32/458_2.png) [@Crafter\_Man](https://boards.straightdope.com/u/Crafter_Man)\ **Post date:** [February 17, 2024, 2:53pm UTC](https://boards.straightdope.com/t/am-i-using-my-watt-meter-correctly/997671/25 "2024-02-17T14:53:34Z")
It’s the same as I described: > The metering engine is given the voltage and current inputs and has a voltage reference, samplers and quantisers followed by an analog to digital conversion section to yield the digitised equivalents of all the inputs. These inputs are then processed using a digital signal processor to calculate the various metering parameters. ([Cite](https://en.wikipedia.org/wiki/Electricity_meter#Electronic)) > Today electronic metering technology uses Digital Signal Sampling of the analogue values of voltage and current and transforms them into a series of digital values, or a series of samples. The more samples in a specific period of time the more accurate the reading. ([Cite](https://blog.intellimeter.com/types-of-electric-meters-and-how-they-work)) ---
**Author:** ![DPRK](https://avatars.discourse-cdn.com/v4/letter/d/4491bb/32.png) [@DPRK](https://boards.straightdope.com/u/DPRK)\ **Post date:** [February 17, 2024, 10:14pm UTC](https://boards.straightdope.com/t/am-i-using-my-watt-meter-correctly/997671/26 "2024-02-17T22:14:32Z")
If it is relevant, I assume you have to know exactly what they charge you for a low “power factor” or for a really crazy load. ---
**Author:** ![Arjuna34](https://avatars.discourse-cdn.com/v4/letter/a/eb8c5e/32.png) [@Arjuna34](https://boards.straightdope.com/u/Arjuna34)\ **Post date:** [February 17, 2024, 10:36pm UTC](https://boards.straightdope.com/t/am-i-using-my-watt-meter-correctly/997671/27 "2024-02-17T22:36:48Z")
There usually isn’t any surcharge for a low power factor, harmonic distortion, etc. in residential metering. ---
**Author:** ![Crafter\_Man](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/crafter_man/32/458_2.png) [@Crafter\_Man](https://boards.straightdope.com/u/Crafter_Man)\ **Post date:** [February 18, 2024, 1:06am UTC](https://boards.straightdope.com/t/am-i-using-my-watt-meter-correctly/997671/28 "2024-02-18T01:06:00Z")
Yea, so far they haven’t hassled homeowners about poor power factor. Could change in the future, though. [Previous page](https://boards.straightdope.com/t/am-i-using-my-watt-meter-correctly/997671.md?page=1)