This is a Repair Kit for the Leybold PENNINGVAC Transmitter PTR 90 Sensor Gauges. They are designed for vacuum measurement in the pressure range of 750 to 1x10^-9 Torr (1000 to 5×10^-9 mbar). The PENNINGVAC Transmitter PTR 90 Sensor Gauge can be operated in connection with an Leybold Vacuum gauge controller CENTER ONE, CENTER TWO, CENTER THREE or with another controller. Over the whole measuring range, the measuring signal is output as a logarithm of the pressure. The Leybold PENNINGVAC Transmitter PTR-90 Sensor Gauge consists of two separate measurement systems (pirani and cold cathode system) the signals of which are combined in such a way that one measurement signal is output. Note that this Leybold PENNINGVAC Transmitter PTR-90 Sensor Gauge MUST NOT be used for measuring flammable or combustible gases which react in air. Please refer to the Technical Data sheet (pdf) below for more information.