Need to know which pressure you refer to, fuel, radiator cap, tires, evap, ac, cylinder compression, transmission?
normally the gauge should be in the middle.(between hot and cold) that is concider operating temp.
8 PSI min - 80 PSI max
40 on idle up to 60 while on the move.
800 RPM should yield about 25-40 lbs. of oil pressure on a stock motor.
An air gauge measures pressure relative to the atmospheric pressure, while a water gauge measures pressure relative to its own density. Water is denser than air, so the air gauge reading will be 3 times higher than the water gauge due to the difference in reference points for each gauge.
To read an R-134a gauge, first ensure that the gauge is properly connected to the refrigerant system. The gauge typically has two parts: the low-pressure side (blue) and the high-pressure side (red). For the low-pressure side, read the pressure indicated when the system is running; it should be between 25-45 psi for normal operation. For the high-pressure side, readings of 150-250 psi are typical, depending on ambient temperature and system conditions. Always refer to specific manufacturer guidelines for accurate interpretation.
get a oil pressure gauge from the auto store and install it under your dash or where ever you find a place to install it and read the directions on how to install it.
between 35/60 psi.
The oil pressure gauge on a Toyota T100 typically should read between 20 to 60 psi while the engine is running at normal operating temperature. At idle, the pressure may drop to around 10-15 psi, which is generally acceptable. If the gauge indicates significantly lower or higher pressure, it may indicate a problem with the oil system or the gauge itself, and further investigation is recommended. Always refer to the owner's manual for specific guidelines related to your model year.
with your eyes
You need a vacuum gauge and it is reed in inches.
The pressure gauge on a Hayward S240 sand filter should typically read between 8 to 12 psi when the system is running normally. If the pressure rises significantly above this range, it may indicate that the filter is dirty and needs to be backwashed or cleaned. Conversely, a reading below this range may suggest a problem with the pump or a leak in the system. Regular monitoring of the gauge helps maintain optimal filtration performance.