A manometer is a tool to measure pressure in closed systems. Manometers measure different types of pressure, absolute, gauge, and differential. They

generally come in two types, liquid and elastic. These types in turn divide into several models:

-- U-tube manometer

-- Differential U-tube manometer

-- Inverted U-tube manometer

-- Inclined manometer

-- Bourdon pressure gauge

-- Aneroid gauges

To calibrate a manometer, we shall need a reference device with higher accuracy than the device under test. We can use a digital pressure transmitter or even another manometer, as long as it has better accuracy.

Basically, we need to check the measuring range of the manometer under test against the reference device to see if it still falls within an acceptable error margin. To do that, we need to ramp the pressure up and down through the measuring range. Usually, we do 0, 25, 50, 75, and 100 percent.

If a manometer doesn’t measure within the error limits, then we can adjust either the zero or the span. We may need a pointer extractor, so we need to make sure that we have that before we begin it.

To adjust the zero, we may need to remove the parts of the manometer, but only enough to get access to the pointer. For the span, we need to tweak the angular adjustment slots at the bottom of the manometer. Before removing anything, we should mark the o, 25, 50, 75, and 100 percent of the manometer’s measuring range.

To know more about manometers, you can get in touch with our engineers and we will be happy to help.