Comparison testers are used to compare output of Pressure gauges that are under calibration against the ideal pressure output. They can be used to calibrate all pressure types like Hydraulic pressure (liquid), Pneumatic pressure (Gas) as well as Vacuum. Nagman has a wide range of comparison testers for pressure calibration of any type. Comparison testers are very easy to read and the process is very quick and simple in house pressure calibrations. Nagman’s comparison testers can give you a long life with very minimum maintenance. They are ideal for lab use and in house calibrations.