Pressure gauges for the measurement of negative gauge pressure (vacuum pressure gauges)
WIKA pressure gauges cannot only be used for the measurement of positive, but also for the measurement of negative gauge pressure. As soon as the absolute pressure is lower than the atmospheric pressure, one refers to it as negative gauge pressure. Previously, this gauge pressure with a negative sign was also designated as underpressure. In order to avoid misunderstandings which might arise from the sign, the designation ‘underpressure’ is nowadays not used anymore.