The ERM-202 is a single or dual channel polarization extinction ratio (PER) meter. When used with a broadband source, it directly measures PER. Single and dual channel models are available. The single channel instrument can be upgraded to a dual-channel version at a later date. By combining low noise circuitry with a high resolution stepper, the ERM series achieves a PER dynamic range of 50 dB.

These instruments are the first to market with OLED displays, a high contrast bright readout that allows the data to be observed from several feet away. The instruments can be operated from the front panel or via remote control. The operator can choose from 4 measurement speeds to optimize speed or accuracy and can observe multiple parameters on the front panel screen including PER, axis angle, power ratios, and optical power.

The measurement data can be stored and recalled for comparison purposes from the front panel as well. Full digital or remote control is included for unattended or system applications.