Comtorgage mechanical amplifiers are available in (8) English and (8) metric measurement ranges. The English dial faces are white, and the metric dial faces are yellow. Each dial face is clearly marked with the amplifier model number.
The total range of the amplifier should be at least twice the size tolerance of the part being measured, so as to allow for measurement of undersized and oversized parts.
Amplifiers with the same model number or range (such as an English CM2 and a metric CM2M) are interchangeable. However, amplifiers with different ranges are not interchangeable. You should never switch amplifier models to get different readout graduations. If you use the wrong range amplifier with an expansion plug, the measurements will be non-linear, and they will only be accurate at the zero point.
Comtorgage amplifiers are available with color-coded dial faces for acceptable, caution, and unacceptable part size tolerances.
Comtorgage amplifiers are extremely rugged, and they are suitable for use in extremely dirty and oily environments.