I just bought a Fluke 115 for general hobbyist & household use to augment an old Radio Shack 22-181 from the 1980's. The specs say it should be capable of reading in nanofarads (nF) to a resolution of 1 nF over a range of 1000 nF, where it jumps to uF scale. Accuracy for that range is +/- ([% of Reading] + [Counts]) and is stated as 1.9% + 2.
When I attempt to measure a simple Ceramic Disc 104 capacitor (100000 pF) I expect to see somewhere around 100 nF depending on tolerance, quality, etc. and on my old Radio Shack meter I do. On the Fluke in both autoranging and manual nF settings it starts out around 370 nF and climbs to about 1.20 uF (1200 nF). I called Fluke support and they agreed that I should be seeing something closer to 100 nF and told me to take the meter back. I did and got a replacement and it does the same thing. I note that the meter appears to work in all other respects and is very accurate when testing electrolytic caps in the uF range (4.7, 10, 47, 100, 220, etc.).
Is there something I and the Fluke rep are not understanding here? Could anyone who has this meter check a 104 Ceramic Cap and let me know what they get? I'm baffled. If it's a calibration issue it may have been a batch because the serial numbers of the two units are only 42 apart.
Barry