Compare Description Drawings, CAD & Specs Full Scale Range Fitting Type Electrical Connector Availability Price
10 Torr 8 VCR female 9-pin D-sub
10 Torr 8 VCR female 15-pin D-sub
10 Torr NW16 ISO-KF 9-pin D-sub
10 Torr NW16 ISO-KF 15-pin D-sub
100 Torr 8 VCR female 9-pin D-sub
100 Torr 8 VCR female 15-pin D-sub
100 Torr NW16 ISO-KF 9-pin D-sub
100 Torr NW16 ISO-KF 15-pin D-sub
1000 Torr 8 VCR female 15-pin D-sub
1000 Torr NW16 ISO-KF 9-pin D-sub
1000 Torr NW16 ISO-KF 15-pin D-sub

Configuration Options

728A Absolute Capacitance Manometer, Compact, 1-1000 Torr, 100C, 728A Series


  • Type
    Pressure Transducer
  • Sensor Type
    Capacitance Manometer
  • Measurement Type
  • Full Scale Pressure Ranges
    1, 2, 10, 30, 50, 100, 200, 500, and 1000 Torr and metric equivalents
  • Sensor Temperature
  • Fitting Type
    Standard: ½ inch OD Tube, Optional: 8 VCR® female, 8 VCO® female, NW16-KF, or 1.33 inch OD CF
  • Output
    0-10 VDC analog into > 10K ohm load
  • Electrical Connector
    15-pin D-subminiature or 9-pin D-subminiature
  • Accuracy
    0.50% of reading (10 to 1000 Torr ranges)
    1.0% reading (<10 Torr ranges)
  • Response Time
    < 75 msec
  • Zero Temperature Coefficient
    0.004% of Full Scale/°C for 0.10 Torr
    0.010% of Full Scale/°C for <10 Torr
  • Span Temperature Coefficient
    0.030% of Full Scale/°C for 0.10 Torr
    0.040% Full Scale/°C for <10 Torr
  • Operating Temperature
    15 to 50°C
  • Overpressure Limit
    45 psia or 2x Full Scale range, whichever is greater
  • Burst Pressure
    10x Full Scale range or 90 psi, whichever is greater
  • Materials Exposed to Process Gases
    Inconel® nickel alloy
  • Power Requirements
    ±15VDC ±5% @ 400 mA max


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.

Gas independent pressure measurement with a Baratron® capacitance manometer. Schematic shows the internal components and functional zones.

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.

Absolute Pressure Measurement

These Baratron® pressure transducers are referenced to vacuum for absolute pressure measurement. Applications include: vacuum furnaces, freeze-drying of fruits and vegetables, gas lasers, automotive component testing, bottle coatings, and vacuum distillation.

Corrosion Resistant Inconel® Construction

All-metal, all-welded construction exposes only Inconel and stainless steel to the gas media. This allows for high overpressure tolerances that reduce errors due to line pressure spikes. High burst pressure ratings contribute to overall system safety.

Internally Heated to 100°C

These capacitance manometers are internally heated for improved accuracy. Unheated versions are exposed to ambient temperature variations which can degrade the sensor accuracy. These devices have the sensor enclosed in a volume that is maintained at a constant temperature above ambient. This solution improves the manometer’s accuracy and repeatability and lowers instrument drift by reducing or eliminating process contamination within the manometer. Heated manometers are recommended for applications that require maximum accuracy and repeatability, operate above ambient temperature and for those processes that employ hot gases.

Pin-Out Assignments

Pin No. 15-Pin Version 9-Pin Version
1 No Connection Pressure Output
2 Pressure Output No Connection
3 No Connection No Connection
4 No Connection +15V/+24V
5 Power Return -15V
6 -15V No Connection
7 +15V/+24V No Connection
8 No Connection Pressure Return
9 No Connection Power Return
10 No Connection N/A
11 No Connection N/A
12 Pressure Return N/A
13 No Connection N/A
14 No Connection N/A
15 No Connection N/A

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