Looking for Magazine article on how to check accuracy of tachometer

[Mark Kenyon]

Two or three years ago I read an article in a yachting or boating magazine about how to check the accuracy of a boats tachometer using a contactless optical sensor using a small electronic circuit and a digital multimeter with frequency measurement. I thought that it was in PBO but have checked all the back issues I have and have been unable to locate it.

Recently, I suspect the tachometer on my barge is reading low and want to check.

I would be very grateful if somebody remembers where the article was published so that I can try to get a copy of it.

Many thanks,

Mark.

 

[alan_d]

Recently, I suspect the tachometer on my barge is reading low and want to check.

Not answering the question that you asked, but have you thought about buying a digital tachometer from Amazon or similar? http://www.amazon.co.uk/HDE-Digital...1386124898&sr=8-4&keywords=digital+tachometer

 

[onesea]

Not answering the question that you asked, but have you thought about buying a digital tachometer from Amazon or similar? http://www.amazon.co.uk/HDE-Digital...1386124898&sr=8-4&keywords=digital+tachometer

Heaven for bid why would he want to do that:

Back issues cost £6.95 each and can be obtained by.....
HDE RPM Digital Laser Photo Tachometer Speed Gauge Non Contact Tach £8.88

Its not even 2 pound more expensive :nonchalance: than a back issue and he would get a handy tool included as well :encouragement:.

 

[nigelmercier]

This one is the same, but cheaper: http://www.amazon.co.uk/exec/obidos/ASIN/B00BY9C1E4/dolcetto-21

No need for an article, just point it at the crank pulley.

 

[Bodach na mara]

This one is the same, but cheaper: http://www.amazon.co.uk/exec/obidos/ASIN/B00BY9C1E4/dolcetto-21

No need for an article, just point it at the crank pulley.

I'd love to know how those things work. All the ones that I have met use a reflective sticky pad on the rotating object to give a repeating flash of reflected light. I got some ICs to build one but ran out of time and lost interest before I completed it. Must have cost me at least a fiver as well! I might just get one of those in the link.

 

[Bilgediver]

I'd love to know how those things work. All the ones that I have met use a reflective sticky pad on the rotating object to give a repeating flash of reflected light. I got some ICs to build one but ran out of time and lost interest before I completed it. Must have cost me at least a fiver as well! I might just get one of those in the link.

That is how they work...Maybe also paint a white mark.

 

[Mark Kenyon]

Many thanks folks. Must be getting older or more stupid - never thought of going down this path.

Like Wright Dawn, I purchased the components but then misplaced the article on how to build it. A self-contained unit would be much more useful. A no-brainer.

Ciao,

Mark.