Compared with MST770, this one has two testers, one is for good plug, another one is for bad, user could compare the difference

 

1. Precautions

1.1 The product is a high-voltage detector, so when the detectors are not in use, be sure to take the battery out to avoid danger.

1.2 If the discontinuous state appears in the process of using, that is normal, please loosen the switch with 3 seconds, you can continue to use.

 

2.Test Principle

In automobile ignition system, the high-voltage ignition coil generates a high-voltage (10,000 volts or more), and the spark plug diverts it from high-tension ignition coil into the cylinder engine, spark between the spark plug electrodes will ignite the mixture. The detector could tell the good spark plugs from the bad by the strength of the spark.

 

3. Test Method

1). Place the spark plug on the pedestal

2). Power-on

3). Press the key switch, the red LED will illuminate and the good spark plug will generate a strong spark and the bad will generate a faint one or not .

4). Loosen the key switch, take the spark plug down the tester by pinching the bottom of it.

 

4. Accessories

1. 12V linear regulator

2. Operating Manual