Types of stopwatch

A stopwatch is a time measuring device that’s commonly used in our everyday life, usually, it is divided into three types - digital, mechanical, and electrical. And currently, the most common ones we can see in the market are 401/405/407/408 pointer electrical stopwatch, 411 digital millisecond meter, 415/417/417B digital electrical stopwatch.

Tips to select a stopwatch calibrator

Instruments that can calibrate stopwatches are named stopwatch calibrators, usually working together with a fixture. It can make a stopwatch start, stop or return to zero adopting the control circuit and output circuit, with OCXO as the standard time source, so as to achieve the aim of calibrating stopwatches. Here are some tips to select stopwatch calibrators as follows for your reference:

1. National standard

SF2002 Stopwatch Calibrator is totally designed according to China JJG237-2010 Standard. If you need another national standard, please firstly compare it with this.

2. High accuracy OCXO

OCXO is built in the stopwatch calibrator and it is important for time intervals. The higher accuracy it has, the better it is. SF2002 Stopwatch Calibrator adopts 10MHz OCXO with accuracy≤5×10-8, which is higher than the one specified in JJG237-2010 Standard. In addition, it has excellent second stability and aging rate, which is more helpful for long time calibrating.

3. External frequency standard

Although the OCXO in a stopwatch calibrator is very accurate for calibrating stopwatches or timers, sometimes higher accuracy is still needed in the actual calibrating job, therefore, a stopwatch calibrator with an external frequency standard will be a better choice.

Fortunately, the SF2002 stopwatch calibrator reserves a 10MHz input terminal in the rear panel to meet this requirement. Please switch the Nominal Frequency at the rear panel to EXT, and input a 10MHz signal with 0V-0.5V (Low)& 3.3V-5V(High) amplitude, then SF2002 can make higher accuracy calibration.

4. To calibrate more kinds of timer/stopwatch

This is a very important factor for users to consider when selecting a suitable calibrator. The following pictures will take you to see the real working status when SF2002 calibrates different stopwatches.

① To calibrate mechanical stopwatch

② To calibrate digital stopwatch

③ To calibrate pointer electrical stopwatch -405 timer

If you need more specification or technical support for this product, welcome to contact Suin. As a specialist in electrical test and measurement instruments, Suin team will do its best to meet all of your needs.