Tachometers are used to measure the rotation speed of shafts or disks (the kind which might be found in motors or machines). Tachometers on vehicles, for example, show the rotation rate of the engine's crankshaft.
you can buy tachometer online , there are lots of sites available, you can check on this ColeParmer.com/Tachometers or www.Davis.com/Tachometers
redundant at best
There are many different models of portable tachometers. Most of them are about as big as a large cell phone.
www.checkline.com provides the opportunity of comparision of portable tachometers. they offer a complete line of Tachometer, Contact Tachometer and Combination Digital Hand-Held Tachometer.
Here's a site where you can buy a handheld tachometer: http://www.checkline.com/tachometers/
It is hard to find people who can repair technical equipment like portable tachometers. However there are many online service that will allow you to mail them and have them repaired for you. Try this site here: www.onlyprotools.com . i am assuming a mechanic would know how to fix that, since tachometers are auto related!
not all Toyota corolla's come with tachometers but if it has one it will be on the left side of the gauge panel next to the speedometer.
They are, but only if hooked up to your car correctly. Make sure it's professionally installed.
RPM is the abbreviation for revolutions per minute and is a measurement of the revolutions of the engine crankshaft. Literally, if your "RPMs stop working" your motor isn't running. However, you are probably referring to the tachometer, the meter that displays the number of rpm's your engine turns, that has stopped working. There are two basic types of tachometers: electrical and mechanical. Electrical tachometers calculate the engine speed by counting electrical pulses while the mechanical tachometers have a mechanical cable attaching to the engine, generally the ignition distributor or camshaft. So, if your tachometer is not working you have either have an electrical problem, a broken cable or the meter itself has become defective.
www.Amazon.com seems to have some pretty good tachometers. They also have the option of buying a used one if a new one is slightly out of budget.
A hall current sensor produces voltage by means of the "hall effect". It is used in automobile applications such as wheel speed sensors, tachometers, speedometers and ignition.