Corrater

Linear polarization instruments provide an instantaneous corrosion-rate data, by utilizing polarization phenomena. These instruments are commercially available as two-electrode Corrater and three electrode Pairmeter (Figure 4-472). The instruments are portable, with probes that can be utilized at several locations in the drilling fluid circulatory systems. In both Corrater and Pairmeter, the technique involves monitoring electrical potential of one of the electrodes with respect to one of the other electrodes as a small electrical current is applied. The amount of applied current necessary to change potential (no more than 10 to 20 mV) is proportional to corrosion intensity. The electronic meter converts the amount of current to read out a number that represents the corrosion rate in mpy. Before recording the data, sufficient time should be allowed for the electrodes to reach equilibrium with the environment. The corrosion-rate reading obtained by these instruments is due to corrosion of the probe element at that instant [184]. 

Review water treatment program history, including corrosion monitoring results using metal coupons or Corrator probes (or similar ones). 

The Corrator from Rohrback Cosasco is the most widely known brand of LPRM equipment. Other manufacturers include Hercules/Betz-Dear-born and Metal Samples. 

One of several different types of equipment used for monitoring corrosion in a cooling system, often on-line and real time. Best known example is the Corrator , which uses a probe and instrument to provide a direct... 

Model 9030 Corrater Corrosion Rate Monitor, User Manual, Rohrback Cosasco Systems, Santa Fe Springs, CA, 1987... 

CORRATOR - A device or probe employed to measure current flow in a process flow. It consists of two identical electrodes, to which a small current is applied and measured, from which corrosion rates can be caicuiated. 

Instruments such as hydrogen probe, corrosometer, corrater, pirameter, galvanic probe, and oxygen meter... 

Instruments for polarization-resistance-type corrosion measurements are commercially available as the Corrater and the Pairmeter. The instruments translate polarization resistance data into corrosion rates and are known as instantaneous corrosion-rate meters. The polarization resistance method is also reviewed in an NACE Task Group report, with a complete bibliography. 

The wheel test requires two phases closely approximating the actual environment of interest (the actual fluids, if possible), and a clean specimen of metal in the form of coupons, Corrater electrodes or Corrosometer probes. Use of the Corrater or Corrosometer permits the use of prerusted surfaces if these are necessary in the evaluation of the inhibitor. 

While the use of Corrater electrodes and Corrosometer probes in laboratory testing is described in the literature, these sensing methods are more useful under field conditions, where rapid evaluation in the actual environment is desired, rather than laboratory testing under accelerated conditions. 

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