MKS 627D Series Capacitance Manometers

Technical Dossier

Product Details And Specifications

MKS 627D Series: Comprehensive Module Range and Technical Overview

The MKS 627D series capacitance manometer is a precision absolute pressure transducer deployed across the most demanding process environments in global heavy industry: semiconductor fabrication, chemical vapor deposition (CVD), thin-film deposition, flat panel display manufacturing, solar cell production, and high-purity gas handling in petrochemical and pharmaceutical facilities. The 627D platform is the direct successor to the MKS 622 and 626 series and has accumulated decades of installed base in OEM vacuum systems, process chambers, and gas delivery panels worldwide. Its Inconel sensor diaphragm and temperature-controlled sensor head (at 45°C or 100°C depending on variant) deliver measurement stability across full-scale ranges from 1 Torr to 1000 Torr, making it the reference instrument for process engineers requiring traceable, drift-resistant pressure data in ISO Class 1–5 cleanrooms and high-vacuum process lines.

The Evolution of 627D Architecture

The MKS 627D series was introduced as a platform consolidation of the earlier 622 and 626 capacitance manometer families, standardizing the mechanical interface, electrical output, and thermal control architecture across a unified product line. Early 627 variants used a 15-pin D-sub connector and analog voltage output (0–10 VDC), compatible with legacy MKS 247, 252, and 651 process controllers. Subsequent revisions introduced the 627D designation, reflecting an updated sensor head geometry with improved thermal uniformity and reduced zero drift. The 627D01TDC1B variant specifically encodes: full-scale range 1 Torr (01), Inconel diaphragm (T), 45°C sensor temperature (D), capacitance sensing (C), 15-pin D-sub connector (1), and analog output with RS-485 (B). Later platform evolution produced the MKS 628B and 629B series for higher-pressure and corrosive-gas applications, and the Baratron 626C for ultra-high-purity semiconductor nodes. For systems requiring digital fieldbus integration, MKS introduced the 627D with DeviceNet and EtherCAT output options. End-of-life for the standard 627D analog variants was announced by MKS Instruments, placing the entire series in the mature/sustaining lifecycle phase. Replacement recommendations from MKS point to the 628B and 722B series; however, the 627D remains the only drop-in compatible transducer for a large installed base of legacy OEM vacuum systems where mechanical and electrical re-engineering is not feasible.

627D Full Catalog & Functionalities (SKU List)

The following SKUs represent verified, commonly sourced models within the MKS 627D capacitance manometer series. Each model is identified by its full-scale pressure range, diaphragm material, sensor temperature, and output configuration.

627D01TDC1B: 1 Torr FS, Inconel diaphragm, 45°C, analog 0–10V + RS-485
627D02TDC1B: 2 Torr FS, Inconel diaphragm, 45°C, analog 0–10V + RS-485
627D10TDC1B: 10 Torr FS, Inconel diaphragm, 45°C, analog 0–10V + RS-485
627D20TDC1B: 20 Torr FS, Inconel diaphragm, 45°C, analog 0–10V + RS-485
627D100TDC1B: 100 Torr FS, Inconel diaphragm, 45°C, analog 0–10V + RS-485
627D1000TDC1B: 1000 Torr FS, Inconel diaphragm, 45°C, analog 0–10V + RS-485
627D01TDC1A: 1 Torr FS, Inconel diaphragm, 45°C, analog 0–10V only
627D10TDC1A: 10 Torr FS, Inconel diaphragm, 45°C, analog 0–10V only
627D100TDC1A: 100 Torr FS, Inconel diaphragm, 45°C, analog 0–10V only
627D01TEC1B: 1 Torr FS, Inconel diaphragm, 100°C sensor temp, analog + RS-485
627D10TEC1B: 10 Torr FS, Inconel diaphragm, 100°C sensor temp, analog + RS-485
627D100TEC1B: 100 Torr FS, Inconel diaphragm, 100°C sensor temp, analog + RS-485
627D01TAC1B: 1 Torr FS, Inconel diaphragm, unheated, analog 0–10V + RS-485
627D10TAC1B: 10 Torr FS, Inconel diaphragm, unheated, analog 0–10V + RS-485
627D100TAC1B: 100 Torr FS, Inconel diaphragm, unheated, analog 0–10V + RS-485
627D01TDC2B: 1 Torr FS, Inconel diaphragm, 45°C, 25-pin D-sub connector variant
627D10TDC2B: 10 Torr FS, Inconel diaphragm, 45°C, 25-pin D-sub connector variant

Sourcing Hard-to-Find & Obsolete 627D Series Parts

The MKS 627D series has entered the sustaining/mature lifecycle phase. MKS Instruments no longer manufactures the full range of 627D variants as standard catalog items, and lead times for new-build units through authorized distribution channels can exceed 16–26 weeks. For facilities operating legacy CVD, PVD, or etch chambers with 627D-based pressure control loops, unplanned transducer failure creates immediate process downtime risk. DriveKNMS maintains a dedicated inventory of tested 627D units sourced through certified secondary market channels, including pull-from-service units from decommissioned OEM systems and new-old-stock (NOS) units from verified industrial surplus. All units are cataloged by full part number, including range code, diaphragm material, temperature class, connector type, and output variant, ensuring exact-match replacement without process re-qualification. DriveKNMS provides lifecycle extension support for the 627D series with a standard 12-month warranty on all shipped units and cross-reference assistance for identifying compatible 628B or 722B upgrade paths where process conditions permit.

Quality Control for the 627D Range

Capacitance manometers require specialized test procedures that differ fundamentally from strain-gauge or piezoelectric pressure sensors. DriveKNMS applies a multi-stage verification protocol to all 627D units prior to shipment. Each unit undergoes a 24-hour thermal soak at the rated sensor head temperature (45°C or 100°C as applicable) to stabilize the capacitance bridge before calibration. Zero-point and full-scale calibration is performed against a NIST-traceable reference standard using a precision dead-weight tester or a calibrated reference transducer at five pressure points across the full measurement range. RS-485 communication integrity is verified by command-response cycling through the MKS Type 937A or equivalent interface. Diaphragm integrity is confirmed by helium leak testing at the process port and electrical feedthrough. Units exhibiting zero drift exceeding ±0.1% of full scale, non-linearity above ±0.25% FS, or communication timeout errors are quarantined and not shipped. Calibration certificates with traceability documentation are available upon request for all 627D units.