Product Overview
The MKS 628A11TBE is a heated absolute capacitance manometer from MKS Instruments, part of the Baratron® Type 628A family of temperature-controlled vacuum measurement instruments. Unlike conventional pressure transmitters that rely on piezoresistive or strain-gauge sensing elements, the MKS 628A11TBE employs a single-sided, dual-electrode Inconel® capacitance diaphragm sensor that measures absolute pressure directly and independently of gas composition. The sensing head is actively regulated at 100°C—more than double the 45°C control temperature used on the 627 series—specifically to prevent condensable process byproducts from depositing on the diaphragm and to eliminate zero drift caused by ambient temperature fluctuations .
The MKS 628A11TBE is configured for a full-scale range of 10 Torr (approximately 13.3 mbar or 1.33 kPa), with a usable measurement range extending down to 0.001 Torr (1 × 10⁻⁴ of full scale). This four-decade dynamic range, combined with ±0.25% of reading accuracy, makes the MKS 628A11TBE suitable for vacuum processes where both base pressure and operating pressure must be monitored with a single instrument. The transducer outputs a linear 0 to +10 VDC signal into loads of 10 kΩ or greater, powered by a ±15 VDC supply drawing up to 500 mA .
The MKS 628A11TBE carries a part-number code that decodes as follows: “628A” designates the heated 100°C Baratron series, “11T” specifies the 10 Torr full-scale range, “B” selects the Swagelok 8-VCR® female process fitting (NW-16 KF flange also available in this family), and “E” denotes ±0.25% of reading accuracy. All wetted surfaces are Inconel®, allowing the MKS 628A11TBE to handle corrosive, dirty, or polymerizing process gases without contamination or sensor degradation. The metal housing incorporates internal surge and ESD suppression networks plus RFI filtering on all inputs and outputs, ensuring reliable operation in the electrically noisy environments typical of plasma process tools .
Technical Specifications
| Parameter Name | Parameter Value |
|---|---|
| Product Model | 628A11TBE (Baratron® Type 628A) |
| Manufacturer | MKS Instruments, Inc. (Andover, MA, USA) |
| Product Category | Heated Absolute Capacitance Manometer |
| Full Scale Range | 10 Torr (code 11T; approx. 13.3 mbar / 1.33 kPa) |
| Usable Measurement Range | Down to 0.001 Torr (1 × 10⁻⁴ of F.S.) |
| Accuracy | ±0.25% of Reading (code E) |
| Sensor Technology | Single-Sided, Dual-Electrode Inconel® Capacitance Diaphragm |
| Temperature Control | 100°C Regulated Sensor Head |
| Input Voltage | ±15 VDC (±5%) @ 500 mA (maximum) |
| Output Signal | 0 to +10 VDC into > 10 kΩ Load |
| Overpressure Limit (No Damage) | 45 psia (310 kPa) |
| Wetted Materials | Inconel® (all process-exposed surfaces) |
| Process Connection | Swagelok 8-VCR® Female (code B) |
| Electrical Connector | 15-Pin Type “D” |
| Response Time (Time Constant) | < 20 msec |
| Zero Temperature Coefficient | 0.002% F.S./°C |
| Span Temperature Coefficient | 0.02% Reading/°C |
| Ambient Operating Temperature | 20° to 70°C (68° to 158°F) |
| Internal Volume (Process Side) | 6.3 cc |
