The CT6 tester consists of an electrical resistance tester (Ohm, Ω) which emits an acoustic signal proportional to the magnitude of the measurement. If the resistance value is small, the device will emit a high-pitched signal. If the resistance value is too high, it will emit a low signal.
At the same time, the CT6 equipment incorporates a LED indicating the magnitude of the measurement in the upper part next to the loudspeaker. This LED blinks in proportion to the magnitude of the measurement, blinking slowly at high resistive values and blinking continuously and rapidly, even remaining lit at low electrical resistance values.