The 221BD-00100A Baratron® Bakeable Differential Capacitance Manometer features 100 Torr (100 mm Hg) full scale pressure measurement and a 0.5 inch OD tube fitting. It offers a reliable, accurate, inexpensive solution to measuring low differential pressures. Operating on the variable capacitance technique, the 221 all-metal sensor contains a tensioned metal diaphragm, one side of which is exposed to the gas whose pressure is to be measured (Px side). The other side (reference, or Pr, side) is adjacent to an electrode assembly which is terminated in another like port. The diaphragm deflects with changing differential pressure, causing a capacitance change between the diaphragm and the adjacent electrode assembly. The capacitance change with pressure generates an AC voltage which is amplified, demodulated, and converted into a high level DC voltage output, linear with pressure, and calibrated against a pressure standard. The electronics of the 221 are housed remotely from the sensor, allowing it to be baked at 200°C (with interconnecting cable removed). An MKS or user-supplied power supply/readout is required to operate the 221.