IPhone Video Tachometer

[T. J.]

I thought I would share this app that I discovered today. Its called Video Tachometer, and that's exactly what it is. It uses the phone's camera and measures rotational speed by altering the frame rate - you adjust the frame rate manually and when the image stops moving, you have the speed. It measures in Hertz or RPMs. The free version has a 10 RPM resolution and the paid version has a 1 RPM resolution. I used the free version today to check the speed of a centrifuge and it worked great. It works for iPhone 5s and newer.

 

[DavidR8]

Another option is called Strobelight which uses the phone light to 'freeze' a mark on a spindle etc.
Works well.

 

[main_cogg]

Thanks for posting, I occasionally could use a tach. I guess that because I'm an old fart I don't automatically think " wonder if there's an app for that ".

 

[FanMan]

There are similar apps for Android, too. I've also used "EngineRPM" for Android, it measures IC engine speed, you tell it how many cylinders and 2- or 4-stroke and it figures it out from the exhaust sound.

 

[Ulma Doctor]

i still use an old Briggs & Stratton vibration tachometer



it's really cool, you twist the 2 halves of the tach, and a wire protrudes out of the body of the tach.
the extended wire vibrates furiously when place on rotating things
by varying the length of the wire, it causes the wire to make small circles
when the circles become very small, the tach will display RPM on a bezel on the interior of the tach.
the resolution is about 100 rpms
i paid $7 for mine in 1992, they are about $25 now

 

[FanMan]

Sounds like the old "Vibra-Tak" which used the same vibrating wire but with a linear slide.

... and looks like they're still made.

http://vibra-tak.com/

 

[Ulma Doctor]

i just got the Video Tachometer on the app store

thanks for the tip @T. J.

 

[ltlvt]

i just got the Video Tachometer on the app store

thanks for the tip @T. J.

I just downloaded and installed on my I-Phone but still trying to figure out how to use it.

 

[T. J.]

I just downloaded and installed on my I-Phone but still trying to figure out how to use it.

Once you have the app open, swipe left to the next menu and press the “?” button. It will give you some links to YouTube videos explaining how it works.

 

[ltlvt]

I think I may have figured it out. I bought the $2.99 app and it seems to work better. If I am doing it right the stripe is supposed to freeze when you have the correct speed and when you go over that speed it appears to rotate backwards Does, this sound right?