Test continuity with a multimeter
Continuity checking is used to testing the connection : shorted condition of wire , switch contacts , relay contacts , PCB trace. Both analog and digital multimeter has continuity test function. Some model of digital multimeter has not continuity check , in this case , you can use Ohm range to check continuous of components. Note that continuity check is a testing when there is not voltage present on component so make sure if the component is unplug , switch off .
Step to Continuity check.
1. Rotate range switch to BUZZ ( X1) range.
2. Check multimer is ready to use by 0 ohm adjustment ; shorted 2 test leads then the buzzer will sound and at the same time LED light up this means multimeter is ready to test.
3. Make sure that if there is not any voltage present at component under test , unplug or switch off should do before testing. The multimeter will damage if there is voltage while doing continuity check.
4. Touch the test leads with component under test. For example AC power cord , the buzzer will sound and LED light up if it is a good AC power cord.
5. In case of checking relay contacts , switch contact. It depend on contacts type.
NC Contact type ( normally close) , the buzzer must sound , mean good contacts. If there is not any sound heard , mean bad contacts. NO Contact type ( normally open ) , the buzzer must not sound , mean good contact. If there is sound heard , mean bad contact.
Read more topics of testing , from here.
