The first step in testing a laser tube is building a testing station. The terminal blocks were hooked up to a 5V source, an input source, ground, and a protection switch.

The protection switch is usually something similar to a water flow switch. FTL goes to low, and FTH goes to high. We are using a high voltage probe which will show the voltage of the power tube in watts. It is basically a voltage divider.

The voltage probe will multiply by 1000 to give an accurate reading of voltage.

Note: You don't want to put your finger anywhere near the high tension lead. It can shock you.

The other instrument we're using is a calorometer, which measures heat. In this case we want to know how much power is being produced by the laser tube for a given input of electrical energy. The body absorbs heat for a certain amount of time for the heat to fully be absorbed.

We moved the tube toward the front of the rig in order to balance it while measuring the heat. When we tested the 40W tube and power supply, we noticed the voltage was constant with the setting of the potentiometer. The voltage did not vary, but rather the average.

However, we noticed with an 80W tube and power supply, the voltage did actually change with we adjusted the potentiometer as well as the amperage.

It is important to note that the potentiometer is not a reliable measurement tool because it has a margin of error (tolerance). An ammeter is the better tool to use to get an accurate reading.