Description
Product Introduction
The Granville-Phillips 275806-EU is a self-contained, compact vacuum gauge module built for precision pressure measurement in industrial vacuum processes. Combining a Convectron thermal conductivity sensor with onboard control electronics, this unit eliminates the need for expensive, external rack-mounted controllers. The “806” configuration features an industry-standard NW25KF vacuum flange, while the “-EU” designation ensures compliance with European CE electromagnetic compatibility (EMC) standards.
Unlike standard Pirani gauges that lose sensitivity above 10 Torr, the 275806-EU utilizes convection-enhanced heat loss to deliver continuous accuracy straight through to atmospheric pressure. This makes it an ideal fit for load lock pump-down monitoring, vacuum furnace control, and thin-film deposition equipment where fast response times and compact footprint are non-negotiable.
Key Technical Specifications
| Parameter | Value / Technical Specification |
| Measurement Range | 1 \times 10^{-4} Torr to 1000 Torr (1.3 \times 10^{-4} mbar to 1333 mbar) |
| Vacuum Fitting | NW25KF (KF25) Quick-Flange Stainless Steel |
| Analog Output Signal | Non-linear 0.37 to 5.6 VDC (log-linear equivalent curves) |
| Sensor Element Material | Gold-plated Tungsten filament (Convection-enhanced) |
| Operating Power Requirements | 11 to 26 VDC (Typical consumption: ~1.5W) |
| Response Time | < 25 milliseconds for pressure changes in high vacuum |
| Accuracy | \pm 10\% of reading (typical within 10^{-3} to 100 Torr calibrated for N_2/Air) |
| Regulatory Compliance | EU / CE Marked (Eurosuffix designation for EMC compliance) |
| Internal Volume & Material | 316L Stainless Steel casing, < 30 cm^3 volume |
Application Scenarios & The “Trench” Experience
Picture this: It’s 3:00 AM on a high-throughput semiconductor or optical coating line. The PLC halts the process cycle because a legacy vacuum sensor reports a false high-pressure trip during chamber roughing. The diffusion pump interlocks lock up, and your shift supervisor is staring at thousands of dollars of stalled product. Having a spare 275806-EU module on the shelf lets you swap the unit in under ten minutes, clearing the false pressure fault and restoring rough vacuum feedback instantly.
- Semiconductor Load Locks – Roughing Line Monitoring – Tracks chamber pump-down from atmosphere down to crossover pressure before opening high-vacuum gate valves.
- Vacuum Heat Treating & Brazing – Furnace Casing Control – Prevents element burn-out by interlocking heating power to strict pressure setpoints.
- Plasma Processing & Sputtering – Process Gas Backfill – Delivers fast analog feedback to the PLC during initial chamber purge and backfill steps.
Field Case Study: A pharmaceutical freeze-drying facility suffered erratic pressure spikes on a sublimation condenser line due to oil contamination on an older Pirani sensor. The maintenance team swapped the failing unit with a Granville-Phillips 275806-EU. Because of its rugged gold-plated tungsten construction and high-convection geometry, the module stabilized output signals, preventing an emergency batch dump and saving an estimated $80,000 in lost product.
275806-EU
275806-EU
Transparency SOP: Quality Assurance & Testing
We don’t just ship boxes; we test them on actual vacuum test benches.
- Inbound Inspection: Inspect the NW25KF flange face for scratches or pitting, verify the original OEM seal, and confirm anti-counterfeit labels.
- Leak Testing: Mount the module onto a helium mass spectrometer leak detector manifold to verify vacuum tightness down to 1 \times 10^{-9} atm\cdotcc/sec.
- Power-On & Zero Calibration: Apply 24VDC power, pull base vacuum below 10^{-4} Torr, and verify baseline voltage output matches OEM zero offset curves.
- Atmospheric Span Check: Vent the test manifold to dry Nitrogen/Air to confirm full-scale output response at 760 Torr atmosphere.
- Final QC & Packaging: Cap the NW25KF flange with a protective seal, apply ESD-safe wrapping, and pack into custom-foam transit boxes.
The Veteran’s Tech Trap Guide
To be honest, most field failures with this specific gauge stem from physical mounting mistakes rather than electrical component failure. Pay attention to these details:
- ⚠️ Sensor Orientation Matters: Mount the gauge module with the main body vertical and the flange pointing down. If you install it horizontally or upside down, natural convection currents inside the sensor tube change, causing severe measurement errors above 1 Torr!
- ❗ Gas Composition Sensitivity: Convectron gauges are calibrated for Nitrogen/Air. If you are measuring Argon, Helium, or CO2 during a process purge, the actual pressure will be drastically different from the output voltage reading. Failing to use gas correction curves can over-pressurize a vacuum vessel!
- ⚠️ Process Contamination & Oil Vapors: Mounting the gauge directly above a mechanical pump foreline without a baffle will allow oil mist to coat the internal tungsten filament. Once coated, the thermal conductivity drops, causing the unit to read artificially high vacuum.
- ❗ Cable Grounding & EU Compliance: The “-EU” designation requires shielded cabling. Ensure the shield is drain-grounded at the power supply to prevent RF noise from cell phones or variable frequency drives (VFDs) from riding on the analog output signal.
Frequently Asked Questions (FAQ for Conversion)
Q: Does the 275806-EU require a separate external controller box?
A: No. The 275806-EU is an integrated Mini-Convectron module. The sensor element and signal processing electronics are housed together in the same compact unit, accepting raw DC power and outputting a direct analog signal to your PLC or DCS.
Q: What is the mechanical difference between 275806-EU and other 275 series modules?
A: The middle digits define the vacuum fitting. The “806” model specifically features an NW25KF (KF25) flange. Other variations like “807” or “808” feature NW40KF or 1/8″ NPT fittings.
Q: What does the “-EU” suffix indicate on this module?
A: The “-EU” suffix signifies compliance with European CE mark directives for immunity and emissions. Functionally and dimensionally, it replaces standard non-EU 275806 modules directly on the flange.
Q: Can I clean the internal sensor filament if it gets dirty?
A: You can gently flush the sensor cavity with high-purity isopropyl alcohol and allow it to air-dry completely. Never insert a swab, wire, or compressed air nozzle into the flange, or you will snap the fine tungsten filament inside.
Q: Why source New Surplus over waiting for factory lead times?
A: Factory lead times for specialized vacuum instrumentation can stretch for months during supply chain bottlenecks. Our New Surplus inventory consists of genuine, unused Granville-Phillips units ready for immediate dispatch—backed by our full 12-month warranty.
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