Model FH Through-wall Probe Reference Electrode by EDI

For Pressures up to 75 PSI(0.5 MPa) and at Intermittent Temperatures up to 210°F (98°C)


Model FH, with a glass reinforced epoxy (G-10 GRE) extension tube and a 316L stainless steel nipple, is designed for heavy duty usage. It can be used at pressures up to 75 psi (0.5 MPa) and at intermittent temperatures up to 210°F (98°C).

Typical Applications

  • Condenser water boxes, circulating pipe, tanks and pressure vessels.

Model Designation

  • Specify as EDI Model FHz-xxx-n.n, where xxx = element type, n.n = extension lenght, inc and z = size code: 10, 7, 5.


Housing Specifications

  • Model FH10: 1 inch NPT hole
  • Model FH7: 3/4 inch NPT hole
  • Model FH5: 1/2 inch NPT hole

All three variations have a 1 inch NPT thread on the termination side.

Element Types

  • AGG: saturated gelled Ag / AgCl
  • CUG: saturated gelled Cu / CuSO4
  • AGD: open-type Ag / AgCl
  • ZIN: open-type Zinc
  • n.n: extension lenght, inc

Conditions to avoid

  • Exposure to temperatures in excess of 130ºF or below 20ºF may damage the electrode.
  • Exposure to electrolytes containing chlorides (Cu/CuSO4 references only), sulfides or other halides (Cu/CuSO4, Ag/AgCl and Zn references)


Permanent reference electrodes may be stored for up to one year with the vinyl protective cap in place. The cap prevents the membrane from drying out. They should be stored indoors in a location not subject to large temperature variations. For long term storage, it is preferable to keep the uncapped reference immersed in a saturated salt solution or keep the capped reference immersed in water.If the electrodes cannot be stored immersed, then the cap should be removed every six months and the membrane moistened with a saturated salt solution.