The 221B Baratron® is a differential capacitance manometer with remote electronics which allows the sensor head to operate at temperatures up to 150°C. The Type 221's electronics are housed remotely from the sensor, allowing it to be baked at 200°C with the interconnecting cable removed.
Features
Baratron® Capacitance Manometer Technology
Capacitance manometers are electro-mechanical gauges that can measure both pressure and vacuum. The capacitance gauge translates a pressure-modulated movement in a thin diaphragm into an electrical signal proportional to the pressure. The pressure sensor is the thin diaphragm that is exposed to the pressure or vacuum being measured via the inlet tube. An electrode is mounted in the reference cavity behind the diaphragm. Pressure differences between the process and the reference cavity deflect the diaphragm slightly, changing the distance between it and the electrode. Variations in this distance produce variations in the capacitance between the diaphragm and the electrode creating an electrical signal that is proportional to the pressure change. Since differences in the capacitance signal are produced by physical changes within the manometer and not by changes in the gas properties, pressure measurements by the capacitance manometer are independent of the composition of the gas being measured.
Percent of Reading Accuracy
Accuracy is specified as a percent of Reading, not Full Scale, as seen in some of the lower performance devices. Percent of Reading accuracy provides you with an even more accurate output signal in the lower scale of the pressure range, where it is needed most.
Differential Pressure Measurement
Differential capacitance manometers can be connected to any pressure or vacuum source for use as the reference pressure. These manometers read the difference in pressure between the inlet tube and the reference cavity at the backside of the electrode. Differential pressure transducers can be used to measure either the true differential pressure or vacuum between two locations, or the reference side of the product can be left open to provide a true reference to local atmospheric pressure. Applications include air and gas flow measurements for filters and analytical systems, downstream pressure control in thin film processing systems, and automated leak testing systems.
All-Inconel® Wetted Surfaces
These pressure transducers feature all Inconel® construction of the pressure sensor allowing it to operate without damage in virtually any chemical environment, including exposure to halogens, deionized water and steam, and ozone.
0 to 10 VDC Proportional Analog Output
These Baratron® capacitance manometers feature a high-level 0-10 VDC analog output signal that is linear with pressure. This analog output can be interfaced with an MKS pressure controller, an MKS power supply/display instrument, or any instrument that meets these requirements.
High Temperature Sensor with Remote Electronics
The pressure sensor and electronics of these capacitance manometers are separated by an eight foot cable, which allows the electronics to be mounted away from sources of heat. Remote electronics allow the sensor to operate at ambient temperatures up to 150°C. The sensir is also bakeable to 200°C with the cable removed.
14-pin Micro Connector Pin-Outs
| Pin | Description |
|---|---|
| 1 | Chassis Ground |
| 2 | DC Common |
| 3 | No Connection |
| 4 | No Connection |
| 5 | +15 VDC |
| 6 | -15 VDC |
| 7 | Pressure Output |
| 8 | Chassis Ground |
| 9 | DC Common |
| 10-14 | No Connection |
Accessories
Compatible Cables
Power Supplies and Displays
Resources
Literature
221B Baratron® Differential Capacitance Manometer Datasheet(180.2 kB, PDF)
Manuals
221B Baratron® Differential Capacitance Manometer Manual(479.7 kB, PDF) 221B Capacitance Manometer Pin-outs(21.9 kB, PDF)
