SAFETY IS MOST IMPORTANT. IF YOU DO IT WRONG THEN YOU CAN BE ELECTROCUTED. THE HIGH VOLTAGE AND POWER COMBINATION CAN BE LETHAL. FOLLOW THE INSTRUCTIONS BELOW. DO NOT DEVIATE FROM THE INSTRUCTIONS REGARDING SAFETY.
The high voltage laser power supply settings can greatly affect the lifetime of the CO2 glass laser tube. A setting above 30 mA will, in almost all cases, greatly diminish the operational life (changing an expected life of several years to months). Even though the laser tubes are ranked in months, such as the 60 watt tubes, I have had customers use them for years before they finally loose power.
More recently, the higher power CO2 glass laser tubes, above 80 watts, and certainly 100, 130, 150, and 180 watts have been more inclined to have shortened lives because the power supply is improperly set. For example, I had an unscrupulous seller who sold me a 150 watt laser with a power supply set at 34 mA. My Mahoney laser power probe measured 145 watts. Then, I contacted the seller because my multimeter read 34 mA. His engineer said the power supply should be set to 30 mA for full warranty on the tube. After setting to 30 mA, I measured the laser output power and got 129 watts. Then, I contacted the company and returned the laser because the seller had actually sold me a 130 watt laser with a 150 watt price tag.
Whatever your reason for checking the power supply current, the steps are provided to demonstrate a safe manner to take a reading then take action to remedy.