All calibration gauges used here at Leybold have traceability, allowing them to be reliable and accurate. They are finely compared to German National standard reference gauges, which are kept in Cologne. Customers rely on Leybold to supply them with accurate calibration and tracing our calibrations back to these extremely accurate sources provides this.
There are several types of calibration gauges, which all provide different levels of vacuum measurements. Pirani gauges, invented in 1906 are less accurate, with a percentage error of around 15-20% and tend to be used for lower levels of vacuum. Capacitance gauges are useful down to a pressure of 1.33x10-5 and are highly accurate in comparison to Pirani devices, with a percentage error of less that 1%. Higher levels of vacuum require more specialized equipment, such as Ionization gauges. These can measure extremely low pressures (down to 1.33x10-10) at a percentage error of 10%.