How does the oil pressure gage work?

Answer 1

There are two types of oil pressure guages. The one that has been around the longest, yet is still in use is a mechanical guage. The later developed guage is called an electrical guage, the system for which is comprised of an electro-mechanical sensing unit [commonly refered to as a "sending" unit], and electrical circuit, and an electrically operated guage.

On a mechanical gage, oil pressure signal is sent via a small tube to the gage. inside the gage is a hollow curved spring call a Bourdon tube. As pressure increases, it tries to straighten the spring which has a linkage and arm which is connected to a needle which sweeps a calibrated face thus giving you your numbers.

On an electric gage system, a voltage source is sent to the gage which passes through a coil which interfaces with a needle arrangement that moves according to the current flowing through the coil. That current is controlled by the sending unit which is screwed into an oil galley in the engine block. There are differant sensing arrangements but the most common is a variable resistor which allows a calibrated amount of current to go to ground, this is calibrated to the gage face and thus you get your numbers.

First answer by ID3436255234. Last edit by ID3436255234. Question popularity: 57 [recommend question]