Chemical Compatibility

Conductivity / Resistivity Electrode — Water/Aqueous

Strong evidence

Named chemicals

ultrapure waterdistilled waterpotable watercooling tower waterbrackish watersea watersalt wateracids/bases and concentrated cleaners (high cell constant only)

What LibertyCES's vendor documentation shows

The publishable rule of thumb from Signet's own operating-range chart: the higher the cell constant, the more concentrated and aggressive the chemical the electrode is designed for. UPW/USP/rinse water uses the 0.01 cell (2818/2819/2839); bottled water the 0.1 cell; cooling tower waste waters the 1.0 or 10.0 cell; deionization regenerant chemicals, alkali cleaners and acids/bases the 10.0 or 20.0 cell. The salt-water-versus-sea-water divergence is worth flagging honestly: saturated salt water pulls 316SS to F while sea water leaves it at E, so the two are not interchangeable on a datasheet — and that boundary is why Water/Aqueous and the already-captured Salts/Brines family should cross-link rather than absorb each other.

Materials documented for this service

316SS or Titanium body with carbon-fiber-reinforced PTFE insulator and EPDM O-rings (2818-2821)
CPVC body with 316SS electrodes (2822)
316SS with PEEK insulator (2823)
PVDF insulator and process connection (2839-2842)
Hastelloy-C, Monel and Titanium electrodes available on special order
Flowline chart: 316SS rates F on saturated salt water at BOTH 40°C and 80°C, but E on sea water at both — a real, non-obvious divergence between two similar-looking aqueous media

Products cited for this service

GF Signet 2818/2819 (0.01 cell, 0.055-100 µS, 18.2MΩ-10KΩ; R.O., ultrapure water, resistivity)2820 (0.1 cell, 1-1000 µS; deionized/distilled)2821 (1.0 cell, 10-10,000 µS; distilled/drinking water, cooling tower)2822 (10.0 cell, 100-200,000 µS, CPVC body; wastewater, salinity, brackish, sea water)2823 (20.0 cell, 200-400,000 µS, 316SS with PEEK insulator, 150°C @ 6.9 bar; the only cell explicitly rated for acids/bases, cleaners and other concentrated chemicals)2839-2842 (PVDF insulator, dual-threaded, 131°C @ 2.76 bar)2850 universal sensor electronics

Sourced to

data/vendor-sources/gf-signet-instrumentation-catalog.md
data/reference/flowline-chemical-compatibility.csv

Every material and product claim on this page traces to the vendor documentation listed above. Chemical compatibility depends on exact concentration, temperature, and duty cycle — confirm current specifications with the manufacturer and request a spec review before final specification.

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