Uploaded June 2017 | Updated September 2026, 2 weeks ago
Act fast (as in "today") and you can get it for $20 (so long as you're in the US and not too far from a Menards store). For a little more money, this is a better (albeit less portable) option with better safety features than the Victor VC921 I reviewed earlier.
I think this is well worth the money even if you don't get it at the sale price.
I wrote and asked about the protocol. I've got my doubts that General Tools and Instruments will actually supply information about the protocol. Maybe I will be pleasantly surprised. Even if I'm not, I don't expect anything terribly clever to be going on, since the output from the DTM0660 chip is RS232 serial. Thus it may not be too much to hope that the Bluetooth radio presents itself more or less as a serial port. (Worst case, I'll ask Mastech. They've been pretty good about releasing service information.)
FCC ID, in case you want to look at some of the stuff they have on file: YRK-GTITS04 (yes, really -- either someone was putting one past the censors and prudes or they didn't give it any thought). You may have to search on the Grantee code (first three digits/letters) only, although the full ID does show up in the list of products.
This meter is identical to Precision Mastech's MS8238D, although I haven't found any place you can actually buy that version of the meter. It's also very definitely manufactured by Mastech, based on documents submitted to the FCC.
The manual does mention TRMS capability as a bullet point in the feature list, but that is the only mention of it anywhere.
Further reading and watching on that very exciting subject:
en-us.fluke.com/training/training-library/measurements/electricity/what-is-true-rms.html
electronics.stackexchange.com/questions/234539/what-is-the-difference-between-a-multimeter-with-rms-and-one-with-true-rms
en.wikipedia.org/wiki/True_RMS_converter
Knurlgnar24's video: youtube.com/watch?v=7ZzwlklBbKc
Details about the Bluetooth interface device: fccid.io/pdf.php?id=2446314 (not sure if this allows direct links, let me know if it doesn't work for you)
Act fast (as in "today") and you can get it for $20 (so long as you're in the US and not too far from a Menards store). For a little more money, this is a better (albeit less portable) option with better safety features than the Victor VC921 I reviewed earlier.
I think this is well worth the money even if you don't get it at the sale price.
I wrote and asked about the protocol. I've got my doubts that General Tools and Instruments will actually supply information about the protocol. Maybe I will be pleasantly surprised. Even if I'm not, I don't expect anything terribly clever to be going on, since the output from the DTM0660 chip is RS232 serial. Thus it may not be too much to hope that the Bluetooth radio presents itself more or less as a serial port. (Worst case, I'll ask Mastech. They've been pretty good about releasing service information.)
FCC ID, in case you want to look at some of the stuff they have on file: YRK-GTITS04 (yes, really -- either someone was putting one past the censors and prudes or they didn't give it any thought). You may have to search on the Grantee code (first three digits/letters) only, although the full ID does show up in the list of products.
This meter is identical to Precision Mastech's MS8238D, although I haven't found any place you can actually buy that version of the meter. It's also very definitely manufactured by Mastech, based on documents submitted to the FCC.
The manual does mention TRMS capability as a bullet point in the feature list, but that is the only mention of it anywhere.
Further reading and watching on that very exciting subject:
en-us.fluke.com/training/training-library/measurements/electricity/what-is-true-rms.html
electronics.stackexchange.com/questions/234539/what-is-the-difference-between-a-multimeter-with-rms-and-one-with-true-rms
en.wikipedia.org/wiki/True_RMS_converter
Knurlgnar24's video: youtube.com/watch?v=7ZzwlklBbKc
Details about the Bluetooth interface device: fccid.io/pdf.php?id=2446314 (not sure if this allows direct links, let me know if it doesn't work for you)
