Product Description
Technical Specification
Instruction Manual
Data Sheet

Elcometer 331 Half-Cell Meters

These easy to use half-cell meters measure the condition and potential corrosion of rebars and steel structures within concrete.

When corrosion occurs the ferric oxide protective layer surrounding the concrete breaks down allowing an electrochemical reaction between the steel and the concrete.

In the half-cell test, a reference electrode is passed over the surface of the concrete and the potential voltage difference is recorded. These potential voltage readings show where corrosion is likely to be, or is currently present.

Elcometer 331 Model HM: supplied with memory and allows users to store up to 240,000 readings in either linear or grid batches.

Key features:

  • Large, easy to read backlit display: for easy viewing in dark environments
  • Single handed operation: most functions can be accessed & controlled through 4 simple keys
  • Intuitive menus in multiple languages: allows use straight out of the box
  • Rechargeable battery supply: battery packs can be charged inside or outside the gauge
  • Ergonomically shaped case: for ease of use and comfort, with a gentle curve to fit snugly against the hip
  • Powerful CoverMaster™ Software (supplied with the Model HM): ultimate data management tool to store half-cell readings and produce professional reports quickly and easily
Elcometer 331 Half-Cell Meter
Elcometer 331 Half-Cell Meter Kit

Technical Specification

Product Features

Model HM

Half-Cell measurement

Large graphics display with backlight

Multiple language menu structure

Rugged waterproof case (IP65)

Adjustable beep volume & earphone socket

Covermaster software


Date & Time



Linear batch memory

Up to 200 batches of 1000 readings#

Grid batch memory

Up to 240,000 readings#


# Linear batch mode: up to 200 batches of 1,000 readings each Grid batch mode: up to 1,000 batches, maximum number of readings: 240,000


Technical Specification 
Part Number Description


Elcometer 331 Half-Cell Meter Model HM
Power Supply

7.4V battery pack provides up to 32 hours of continuous use (20 hrs if backlight is on). Rechargeable in 4 hours either inside or outside the gauge using an external charger.

Operating temperature

0 to 50°C (32 to 120°F)


230 x 130 x 125mm (9 x 5.1 x 4.9")


1.54kg (3.4lbs)

Packing List

Half Cell Meter, 25m extension cable on spool, 1.7m red rebar connecting cable with connecting clip & 1.7m black half-cell connecting cable, rechargeable battery pack & charger (UK, US & EU), earphone, shoulder strap, plastic carry case & operating instructions.


Model HM is also supplied with Covermaster software and PC cable.



ACI 318, ASTM C876-91, BS1881:201, BS1881:204,  BS8110, CP 110,   DGZfP:B2, DGZfP:B3, DIN 1045, EC2, SIA 262, SS-EN 206, Concrete Society Technical Report 60, UNI 10174


Standards in grey have been superseded but are still recognised in some industries.



331 half cell kit

Half-Cell Kit


Consisting of either a copper electrode in a copper sulphate solution or a silver electrode in a sodium chloride solution, each half cell is a sealed unit - no need to mix chemicals. Supplied with a 25m / 80' cable, every half-cell probe is guaranteed for 5 years.

Part Number



Copper/Copper Sulphate


Silver/Silver Chloride