How to Measure the conduction voltage of led ?

How to Measure the conduction voltage of led ?
You can Measure the conduction voltage of led with multimeter, the step as follws;
First we wanted a adjust power, and it’s series connect with resistance and LED. In here we adopt a smaller on resistance(such as 1 Ohm).now we can Measure the conduction voltage of led .two ends(NOTE: measure the voltage of led no include resistance ) . the follow we began very slowly to increase the input voltage of adjust power(the input voltage from 0 ( zero) up to) . the led luminous rapidly increased when the voltage of adjust power was gradually increase. Another phenomenon that occurs is the voltage of multimeter increase grows slowly. At moment, please take notes that voltage of LED. The record is conduction voltage of LED.