Pirani vacuum gauge with platinum filament

Client: Hezareh-Sevom Company (http://www.hezare-sevom.ir/fa/)

Date: 2014-2017

Director project: Prof. Faramarz Hossein-Babaei

Project type: Industrial implementation

Project collaborator: Ehsan Yousefiazari, Armin Alizadeh

Summary of project:

Pirani sensor is the most commonly utilized vacuum gauge. This device measures low atmospheric pressure by estimating thermal conductivity of the prevailing atmosphere. The nominal measurement range is 0.1-1000 Pa, which partly covers the vacuum range produced by rotary pumps. These gauges present fairly reproducible measurement results in clean atmosphere chambers, but presence of atmospheric contaminations can irreversibly hinder their accuracy. The sensor head in Pirani gauge comprises a metallic filament, the electrical resistance variations of which is monitored with an appropriately designed bridge. Commonly, tungsten wires are utilized for this purpose; we have altered the design to allow using platinum filaments instead. The device is at the stage of industrial production.