Conductivity & Resistivity Sensors for Semiconductor UPW
GF Signet 2818-2823 and 2839-2842 electrodes — explicitly named for semiconductor water production in GF Signet's own literature, rated to the 18.2 MΩ-cm UPW benchmark.
2818-2823 vs. 2839-2842: Accuracy and Named Applications
| Electrode Family | Accuracy | Range | Named Applications |
|---|---|---|---|
| 2818–2823 Conductivity/Resistivity Electrodes | ±2% of reading (certified cells ±1%) | 0.055 to 100 µS / 18.2 MΩ to 10 KΩ / 0.02 to 50 ppm | Semiconductor Water Production, Reverse Osmosis, Deionization, USP Purified Water, Ultra Pure Water |
| 2839–2842 PVDF Electrodes | ±2% with calibration-cert data entered; ±5% with standard cell constant | Same low-conductivity band, PVDF-wetted construction | Semiconductor, Demineralizer |
Specifications quoted directly from GF Signet's own 2818-2823 and 2839-2842 electrode datasheets. Verify current documentation and exact configuration before purchase.
Why Ultrapure Water Monitoring Is a Named GF Signet Application — Not an Adaptation
A lot of industrial conductivity instrumentation gets pressed into UPW service without actually being built for it. GF Signet's 2818-2823 and 2839-2842 lines are different: both datasheets explicitly list "Semiconductor Water Production" and "Semiconductor" among named applications, and both operating-range charts label a UPW band directly on the low-conductivity end of the scale, alongside USP purified water. That's a real, sourced claim from GF Signet's own literature — not a generic industrial sensor with semiconductor use tacked on.
For UPW specifically, contacting-type sensors like these are the correct choice over toroidal (inductive) sensors, which aren't built to resolve the low-µS/high-MΩ range UPW systems operate in.
Field-Verifying Sensor Calibration Without Sending It Out
GF Signet sells a real plug-in NIST-traceable recertification tool line (3-2850.101-1 through -5) that simulates known reference points — 1.0 µS, 2.5 µS, 10.0 µS, 18.2 MΩ, and 10.0 MΩ — for use with the 9900, 9950, 2850, and 8900 transmitters. That means a maintenance team can field-verify a sensor's calibration without pulling it and sending it to a lab, which matters when the alternative is process downtime.
Conductivity/Resistivity Sensor FAQs
What does 18.2 MΩ-cm resistivity mean, and why does it matter?
18.2 MΩ-cm is the theoretical maximum resistivity of pure water at 25°C — the industry benchmark for ultrapure water (UPW) purity. GF Signet's own 2818-2823 and 2839-2842 electrode datasheets explicitly claim this figure and label a UPW band directly on their operating-range charts. A resistivity reading approaching 18.2 MΩ-cm confirms the water is essentially free of dissolved ionic contamination — the standard SEMI F63 references for semiconductor process water.
Does GF Signet explicitly name semiconductor applications in its own literature?
Yes, and this is real — not an inference. Both the 2818-2823 and 2839-2842 datasheets list "Semiconductor Water Production" / "Semiconductor" directly among named applications, alongside Reverse Osmosis, Deionization, and USP Purified Water. This is stated in GF Signet's own product documentation, not third-party marketing.
Should I use a contacting or toroidal conductivity sensor for ultrapure water?
Contacting sensors are the standard choice for UPW's low-conductivity range — toroidal (inductive) sensors are built for higher-conductivity process streams and generally aren't sensitive enough at UPW's low-µS/high-MΩ readings. GF Signet's 2818-2823/2839-2842 lines are contacting-type electrodes for exactly this reason.
What's the accuracy difference between the 2818-2823 and 2839-2842 electrode families?
The 2818-2823 line is rated ±2% of reading (±1% for certified cells). The 2839-2842 PVDF electrodes are rated ±2% only when the actual calibration-certificate data is entered into the transmitter — if you instead use the standard cell constant without entering cert data, accuracy drops to ±5%. Always enter the certificate data if the application needs the tighter spec.
Is there a NIST-traceable way to verify a GF Signet conductivity/resistivity sensor in the field?
Yes — GF Signet sells a real plug-in NIST traceable recertification tool line (3-2850.101-1 through -5), which simulates 1.0 µS, 2.5 µS, 10.0 µS, 18.2 MΩ, and 10.0 MΩ reference points for use with the 9900, 9950, 2850, and 8900 transmitters, letting you field-verify sensor calibration without sending the sensor out. The sensors themselves also ship with NIST-traceable certified cells, and an optional NIST Traceability Certificate is available to meet USP requirements.
What cell constant should I choose for a UPW conductivity sensor?
Lower cell constants (e.g. 0.01 cm⁻¹) are built for low-conductivity/high-resistivity applications like UPW; higher cell constants (0.1, 1.0, 10) suit progressively higher-conductivity process streams. Match the cell constant to the actual conductivity range you expect to measure — an undersized cell constant will read inaccurately outside its intended band.
Need Verified UPW Instrumentation?
Send LibertyCES your target resistivity/conductivity range and where in the loop you need to measure it — we'll verify the right electrode family and transmitter pairing.