The Leybold Thermovac TTR 91 RN Micro-Pirani Transducer has a MEMS-Pirani (Micro-Electro-Mechanical-Systems) sensor which is resilient to vibration and shock venting. The 91 N measures from 3.75 x 10^-5 to 750 Torr for monitoring pump-down cycles. The Thermovac transmitters are active sensors which offer analog voltage output and set point relays (certain models only) for improved process control. On capable models, built in relays allow switching functions to be performed directly by the transmitter without the need of a programable control. The Thermovac series Transmitters are equipped with an LED ring which shows the status of the the sensor. For complete specs and operation information See AVAILABLE DOWNLOADS below.