Portable Corrosion Indicator

Peace of mind available from stock at an affordable price. Share a single unit among vessels within your fleet.

Regular use of the Cathometer Corrosion Control Indicator on steel structures immersed in seawater will:

Measure the level of corrosion activity on steel structures such as offshore platforms, underwater hulls, ballast tanks and docks.
Verify the performance of any cathodic protection system fitted and give warning of the need for anode replacement or other service in advance of docking dates or repair schedules.
Identify unprotected areas in a cathodic protection scheme, such as amidships when fore and aft ICCP systems are installed.
Indicate the compatibility of a cathodic protection system with an underwater paint scheme.

Instrument Characteristics

The Cathometer comprises an easy-to-read millivoltmeter with color-coded scale (calibrated 0-1.5 volt DC full scale and of 40,000 ohms/volt impedance) a stainless steel contact probe and a durable silver/silver chloride reference electrode housed in a perforated PVC enclosure.

The Cathometer is simple to operate by untrained personnel, lightweight (7 lbs.), portable, and compact (11" x 7-1/2" x 5"). The reference cell is attached to 100 feet of flexible cable conveniently located on a reel at the back of the indicator. The instrument is preset and should not require adjustment during service.

The Cathometer is made in the U.S.A.

Indicator Use

For optimum performance, the reference cell should be soaked in a sink or bucket full of seawater for up to 24 hours before use. This is particularly important when the meter has not been used for some time. If in regular use, a small sponge fitted in the bottom of the cell socket maintains the cell in an active condition as long as the sponge remains wet.

Instructions for Use

Detach the reference cell and steel contact probe from the Cathometer casing.
Lower the reference cell into the sea or ballast water. When surveying hulls, readings should be taken when the structure under survey is well clear of other submerged steel structures.
Force the contact probe into a clean (paint and rust free) area of steel. A voltage reading will immediately register.
Record the voltage reading shown on the Cathometer, and the position at which it was taken. A complete survey requires readings to be taken at various levels vertically down the structure, and at as many locations in a horizontal direction as possible.
Regular potential surveys will indicate the rate of deterioration of immersed steel due to corrosion, or alternatively, the effectiveness of any installed Cathodic Protection system.

Reading Interpretation (Saltwater)

0.00 - 0.65V - Under-protection, active corrosion
0.65 - 0.80V - Slight under-protection
0.80 - 1.00V - Complete Cathodic Protection
1.00 - 1.50V - Over-protection, possibly resulting in coating damage.

Rough Instrument Check

Immerse the reference cell in a new zinc galvanized steel bucket full of seawater.
Ground steel probe against the bucket side.
Voltage reading should be in the range of 1.0 - 1.1 volts.

Maintenance

The Cathometer should require no maintenance. However, the meter will be rendered ineffective should damage to the movement of the millivoltmeter or to the inner ceramic shroud of the reference cell occur. Therefore do not subject the Cathometer to rough handling. Remember that it is an instrument, although a robust one.

Contact us for more information or to place an order.