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1. With a small flat head screwdriver, "zero" the volt meter and ammeter (if analog type).

2.Place the auto-ignition switch to "MANUAL".

3. Open the lamphouse door and defeat the door interlock safety switch.

4.Observing proper polarity, connect a calibrated volt meter to the DC power cables.

5.Power on the lamphouse. The bulb should not ignite while the auto-ignition switch is in "MANUAL".

6. Compare the voltage reading from each volt meter. Record the values. Replace the meter in the lamphouse if the values are more then 15% apart from the calibrated volt meter.

Remove the volt meter leads.

7. Press the "STRIKE" button to ignite the lamp OR: If there is no "STRIKE" button:
Flip the auto-ignition switch to "AUTO", then immediately return it to "MANUAL" after the bulb is lit.

Caution: The auto-igniter must be disabled. If the bulb should go out, it can not be allowed to re-ignite automatically and injure someone connecting leads or damage test equipment.

8. Connect the oscilloscope across the ammeter shunt. Set the oscilloscope to 10 millivolts per division; the timebase to 20 milliseconds per division. Avoid using "X10" probes. There are no special triggering requirements, AC or "AUTO" will work.

Note: Since the oscilloscope will be reading DC, greater accuracy can be obtained by adjusting the scope's baseline to the bottom of the screen, rather then to the center.

Caution: Older oscilloscopes with a "third-wire" ground on the power cord may give erratic or incorrect readings. This may be caused when the shield wire of the oscilloscope probe is connected to one side of the shunt. (Effectivly, one side of the DC output is being grounded when the probe shield in connected.) A solution is to isolate the "third-wire" ground on the oscilloscope using a grounding adapter, but this can create an unsafe condition. If you do this, be aware you are working with ungrounded equipment and act accordingly.

Record Imax (total peak voltage) Record Imin (minimum peak voltage) Calculate ripple and record. The percentage of ripple should be less then 5%.

ripple = {Imax - Imin} over Imax times 100%

9. Record the lamphouse ammeter value.
Because the ammeter shunt reduces the actual current value to the lamphouse ammeter by 1/3000, there will be 3 amps for every 1 millivolt shown on the oscilloscope. Therefore, the amperage can be calculated by multiplying Imax, in millivolts, times 3000. For example:

36 mv * 3000 = 108 amps

Note that this test requires an accurate 150 mv shunt.

10.Compare the readings from the ammeter and the calculated current. Record the values. Replace the meter in the lamphouse if the values are more then 15% apart.

11.Return the door safety interlock switch to normal.

Let light leaking from the lamphouse (before the shutter) fall on a silicon solar cell. Use a variable resistor to load the cell to produce an output of about 0.50 volts when fully illuminated. Use an oscilloscope to measure the voltage across the load resistor. If 0.50 volts represents the "steady state" light output, there should be no more than 5% AC "ripple" (0.025 volts peak-to-peak) in the cell's output. Be careful not to let room lights (especially fluorescent) illuminate the cell during the measurement, as they will have considerable AC component.

As the lamp lights the inrush current rise can be graphed and inrush is one of the more distructive items the lamp faces

The ripple is then meausered as the precent fluctuation visible in the waveform

BTW, a scope usually reveals alot of "hash" in the current or voltage waveform being supplied to an operating xenon lamp. The plasma of the arc is not as well behaved as a tungsten lamp.

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