After looking on line for the AMPROBE instruction manual I came to the conclusion that this particular instrument was measuring the peak current & then converting it into a RMS value. An averaging instrument would read the compact fluorescent lamp low, at least the Fluke T6 does at .2A.

Here are a couple more pics of the pair, except this time I have turned on the PEAK HOLD function in the 285. Many upper tier Flukes have this same feature. They can capture transients greater than 250micro-seconds.

Remember the decimal point must be shifted two digits to the left on the Flir285.

Compact Fluorescent Bulb

In first picture the where the AMPROBE is displaying 1.4A the 285 is showing a peak to peak reading of 5.26A (2.62+2.64) . If you divide that by 2.8 a normal sine wave RMS value would be 1.88A. The RMS meter & known value are much lower, around .6A. Looking at the data provided on the 285 one can tell the sides of the sine wave are much steeper than normal.

Incandescent Bulb

In the second picture the AMPROBE is spot on at .6A considering full scale is 200A. The 285 is displaying .656A with a peak to peak value of 1.929A (.966+.963). Again dividing by 2.8 one gets .69A. The sides of this sine wave is pretty much normal. We know the top of the waves are a little flattened out all across the country from a previous thread. That may account for the slight difference between the calculated & measured.

Advise is a dangerous gift, even from the wise to the wise.

## Bookmarks