The HZ-109S is equipped with a high-precision stopwatch with a timing accuracy of up to 0.0001 seconds, which is one of the biggest functional differences between it and a regular current booster - it does not require a separate stopwatch, and the action time and output current are displayed simultaneously on the same screen. But this stopwatch has two working modes, and if you choose the wrong one, you won't be able to measure the effective time.

Dual mode (default)

Default dual mode upon startup.

Working logic: The instrument automatically starts counting internally - at the moment when the "output" button is pressed and the high current starts outputting, the stopwatch automatically starts timing; When the external contact (the action contact of the tested device) is closed (or the potential signal changes), the stopwatch automatically stops counting and displays the action time.

Applicable occasions: Suitable for testing the action time of most relay protections and automatic devices. Taking the thermal relay as an example: press the output button → the thermal relay starts to receive overload current → the thermal relay trips → the action contact closes → the stopwatch stops, and the screen displays the action time of the thermal relay.

Wiring: Connect the action contact of the tested device to the stopwatch input terminal on the instrument panel, and at the same time, turn the "stopwatch contact/potential" switch to the corresponding position (if it is a dry connection point, turn it to the "contact"; if it is a potential signal, turn it to the "potential").

Single channel mode

Move the cursor to the word 'dual path' and press to switch to 'single path'.

Working logic: The external contact (or potential) triggers the start of the meter, and when the same or another contact (or potential) acts again, the meter stops. The output status of the instrument does not participate in timing and is fully controlled by external signals for start and stop.

Applicable occasions: The tested equipment has independent "start" and "action" contacts, or requires a complete record of the entire process time from external signal input to action completion, regardless of the internal output timing of the instrument.

The difference between contact and potential signals

Contact (dry contact): The tested equipment provides a pair of potential free contacts, which are connected to the stopwatch terminal of the instrument. The instrument uses a weak power supply to detect the continuity inside

Potential: When the tested device operates, a potential change occurs at a specific terminal, and the instrument detects this potential change as a trigger signal

The terminal positions of the two signal inputs are the same, distinguished by the "stopwatch contact/potential" switch. Before operation, confirm the type of signal provided by the tested device, and then turn the switch correctly, otherwise the stopwatch will not respond.