RPM LOGGER? EASY PEASY!
Or maybe not.
My primary boiler is Weil McLain Ultra which uses the negative pressure from the draft inducer small variable speed fan to set the Btu output by driving the vacuum-operated gas valve. A common arrangement.
The Ultra is more like a heat exchanger with a computer on top and the fan speed is easily programable.
Wanting to use the Ultra as a lagging backup to the heat pump. The per Btu cost of the boiler is currently about TWICE the cost of the heat pump. Wanting the boiler to ramp up slowly and be limited to 30K Btu/h, which equals ~300 RPM on the draft inducer.
So I had to verify my settings for keeping it on the lower end of the turndown ratio.
—” I was wondering if there was a cheaper option.”
Cheap is my first name, “ME CHEAP CHARLIE NUMBER TEN” a common expression back in RVN.
UT372 non-contact Digital Laser tachometer Data hold Odometer/MAX/MIN/AVG mode;RPM range 10~99999RPM USB interface:
Uni-T Ut372 Digital Laser Photo Non-Contact Tachometer Wide Range Usb Interfa✦Kd
https://t.ly/t8tuF US $57.44 e-bay new free shipping. Also at Newegg $60, still from off shore.
The manual for UT272: https://seli.tn/Doctech/UT372.pdf
Shows the AUTO OFF can be turned off and the interval can be set up to 255 (seconds?)
One of my neighbors said it was best to cut out the middleman and order direct. Even some Tektronix meters have guts from offshore.
Also for your consideration, an inexpensive Arduino RPM logger.
NB: This is on the edge of PROPELLER HEAD territory, not for everyone. I do not claim to be a propeller head, but they allow me into their meetings.
Arduino is an open-source electronics platform based on easy-to-use hardware and software.
Like Legos with jumper wires and sometimes a bit of solider.
Can you use an inductive (tiny spinning magnet)pickup?
Simple demo with tiny magnet.
https://makersportal.com/blog/2018/10/3/arduino-tachometer-using-a-hall-effect-sensor-to-measure-rotations-from-a-fan
Hall effect sensor with a VERY SMALL neodymium magnet glued in place?
Arduino data shield writes to an SD card
Arduino rpm logger or approved equal?
< $30 for a simple tachometer that I THINK MIGHT be made to fit within close proximity to MY fan wheel??? /// The downside he uses a mini Arduino that does NOT accept the standard plug-in ‘shield’ card for data logging to an SD card, ~$10.
RPM Using IR sensor
https://projecthub.arduino.cc/BEASTIDREES62/d4a796a9-5bdf-4d5e-96ae-cd7fce0a4dc7
Just as you have helped me on my off-the-wall project, I had more than a few online helpers plus my brother the computer guru and I used an older Arduino To pick up a dozen temperature sensors from the two boilers and piping system, some years back.
Since then I found a very good price on a TYPE K Omega 8 pair extension cable $$$ to extend the readers to my den next to the computer.
Thank you
Many thanks for your suggestions. The UNI-T UT372 looks like it might do the trick although it’s hard to get concise information as to what they mean with their description of logging. At 1:39 at this video, it looks like it might have some useful features but hard to tell since the spec data is so sparse when it comes to talking about the logging. https://www.youtube.com/watch?v=cWI2stg6w80 I see there is also a UT373 but it doesn’t look like it does any logging and doesn’t even have a USB port like the UT372.
One thing I noticed on Amazon is that a reviewer claimed that it can only work on a ‘rotating face’, and doesn’t work on a curved surface like the side of a shaft. That’s a bit of a deficiency for many applications. I’m not sure about that… at this link, a guy reviewed the UT373 and it didn’t look like it had any problems. https://www.youtube.com/watch?v=TZhTI8sjr_U
As for the Arduino, I’ll give that to one of the kids in my office to work on for me!
Thanks again… It may take a while but I’ll let you know how I make out!