I have received some aluminium electrolytic capacitors which are rated at 4.7uF, 20%. When I measure them on my six digit fully calibrated (ie I'm pretty sure this is accurate) LCR Meter they measure from 3.09uF to 3.4uF.
My subcontractor says they're okay because when they reflow them the capacitance increases to just over 3.76 (not sure if they stay high after they cool down). I think he's talking rubbish and they're just plain dud (i.e out of spec).
Can anyone shed any light on this? Are they out of spec, or does reflowing them permanently raise the capacitance?
Appreciate any answers or 'ancient wisdom' going.