MKS 103450010 Pirani Vacuum Gauge — Thermal-Conductivity Pressure Sensor

MKS Instruments · Pirani / HPS® Series · Vacuum Sensor · Worldwide Shipping

The MKS 103450010 is a Pirani-type thermal-conductivity vacuum pressure sensor used to monitor rough and medium vacuum in process tools, load locks, transfer chambers, R&D vacuum systems and analytical instruments. It is widely deployed in semiconductor fabs, photovoltaic lines, vacuum metallurgy, freeze-drying and mass-spectrometer inlets where reliable low-pressure feedback is critical to Allen-Bradley ControlLogix, Siemens SIMATIC S7 and Mitsubishi MELSEC process controllers.

KOEED sources genuine MKS / HPS® Pirani transducers and ships them worldwide with full documentation. Send your instruments list to Moritta@KOEED.COM for a 24-hour quote.

1. Key Technical Specifications & Overview

A Pirani gauge works on the thermal-conductivity principle: a heated filament loses heat to the surrounding gas at a rate that depends on pressure. As pressure falls, fewer gas molecules carry heat away, the filament temperature rises, and the change in resistance is correlated to absolute pressure. This makes the 103450010 the standard workhorse for the 10⁻⁴ mbar to 10³ mbar range.

2. Application Scenarios — Where It Fits

The MKS 103450010 is specified wherever a process step needs a clean, repeatable low-pressure reference signal. In production environments, that signal is fed into a plant-level Allen-Bradley, Omron or Schneider Modicon controller for interlock logic, recipe control, and historian logging. Typical deployments include:

• Semiconductor fab load locks and transfer chambers on Siemens SIMATIC / Mitsubishi MELSEC platforms
• Photovoltaic and thin-film deposition tools interlocked with Fanuc handlers and Yaskawa servo axes
• Vacuum oven, vacuum furnace and brazing furnaces with recipe control on Panasonic FP or KEYENCE PLCs
• Freeze dryers, mass-spectrometer inlets, leak detectors and analytical instrument front-ends
• Coating, sputtering and PVD / PECVD process tools where vacuum ramps are part of the recipe
• Hard-to-find replacement in legacy MKS / HPS® Pirani installations where the OEM sensor is EOL

3. Integration & Wiring Notes

The 103450010 is the sensor head only — it must be paired with a compatible MKS controller (PDR-2000, 901P, 937B, or a Granville-Phillips 275 / 376 / 390) that supplies the bridge excitation, linearization and analog output. The notes below cover the integration decisions that most often cause commissioning delays.

• Sensor cable: use the OEM MKS shielded cable assembly, not a generic twisted pair. Cable length contributes to the bridge balance and to noise pickup on a heated filament.
• Controller pairing: confirm the controller firmware / setpoint table recognizes the 103450010 P/N; legacy PDR-2000 units often need a sensor-type jumper or EPROM update.
• Analog output to PLC: the controller typically exposes 0–10 V or 4–20 mA. Wire to an analog input module and convert with the PLC Analog Calculator to engineering units (mbar / Pa).
• Digital output: newer MKS controllers support RS-232 / RS-485 setpoint queries; map readings into the PLC scan via Modbus RTU when exposed.
• Ground and shielding: bond the sensor body to chamber ground at one point only; route the signal cable away from VFD-driven servo drives (Fanuc, Yaskawa) to avoid coupled noise.
• Vacuum-side cleanliness: Pirani filaments are sensitive to pump oil, photoresist outgassing and process deposits. Mount vertically with the port down where possible and budget for periodic filament replacement in high-cycle processes.

For sensor / controller diagnostics, see the PLC Error Code Database and the AI Diagnostic Tool for 24/7 help interpreting a noisy or stuck Pirani reading.

4. Installation & Commissioning Tips

A clean installation dramatically extends Pirani service life. The MKS 103450010 uses a standard NW25 / KF25 flange, so it mates with most European-style vacuum piping found in semiconductor, R&D and analytical tools. Treat the filament as a consumable — it is replaceable on the MKS platform, not on the tool side.

• Vent the chamber to atmospheric pressure before opening the KF clamp; venting under partial vacuum can suck particulates back into the sensor.
• Use a fresh centering ring (FKM / Viton® or Kalrez® for aggressive chemistries) and a new clamp; do not re-use a nicked ring on a high-vacuum seal.
• After pump-down, run the controller’s automatic zero / atmosphere adjustment sequence with the gauge isolated from the chamber at full vacuum and at dry N₂ atmosphere, respectively.
• Log a baseline reading at atmosphere and at crossover to the next-stage gauge (e.g. cold cathode or Baratron®) so the recipe engineer has a known-good reference curve.
• Validate the analog input wiring end-to-end with a hand-held calibrator before energizing the chamber heaters — many “vacuum drift” tickets in factory automation are actually analog-input scaling errors in the PLC.
• Add the gauge to the preventive-maintenance schedule and keep a spare 103450010 on the shelf if downtime is expensive.

5. Procurement, Warranty & Lead Time

MKS 103450010 Pirani gauges ship in original MKS / HPS® packaging with traceable lot numbers and factory calibration certificates. KOEED is an independent multi-brand industrial-automation distributor (not an OEM subsidiary) — we source genuine MKS sensors through our China sourcing network and re-test on receipt.

• RFQ turnaround: most quotes return within 24 hours on business days — email Moritta@KOEED.COM with the part number, quantity and destination country.
• BOM quotation: send a full instrument list (vacuum gauges, controllers, PLCs, servo drives) and we quote the lot — useful for fabs running mixed-brand lines.
• Lead time: typically 3–7 business days for in-stock items, longer for factory drops. Express options on request.
• Shipping: DHL, FedEx, UPS or air freight worldwide (per the product page title convention) — see the Shipping Policy.
• Warranty: 12-month limited warranty against manufacturing defects; warranty does not cover filament burnout from contamination or operation outside the rated pressure range.
• Hard-to-find / EOL: if the 103450010 is end-of-life at the OEM, ask us — the real-time sales records show what we have shipped recently, and the AI Diagnostic Tool can suggest a drop-in alternative.

For related controllers and accessories, see the MKS Instruments and vacuum sensor collections, and follow our Daily PLC News for end-of-life notices on MKS / HPS® P/Ns.