reading smaller value caps outside tolerance

[pcb rookie]

Curious about the readings i'm getting on lower value caps. Before I begin, I understand I'm not using high $ value devices. This might just be the limit of these devices so I might being trying to be too critical understanding what I'm working with. I'm just wondering if I could expect better readings with better units like the Atlas LCR40 or a Fluke DMM? This is just out of curiosity ...

I get readings outside tolerance value with both the TC1 and my DMM (AstroAI DM6000AR).
I seem to get better reading with the AstroAI DMM but still not within the tolerance.
@1nF, the AstroAI gave an accurate reading but the TC1 was about 10% off.

The 1nF is a Kemet 5% box films caps
All others are TDK 5% MLCC caps

1nF reading 905pF (TC1) / 0.99nF (AstroAI)
680pF reading 622pF (TC1) / 0.66nF (AstroAI)
470pF reading 413pF (TC1) / 0.45nF (AstroAI)
220pF reading 171pF (TC1) / 0.20nF (AstroAI)
100pF reading 57pF (TC1) / 0.08nF (AstroAI)
47pF reading "no, unknown or damaged part" (TC1) / 0.02nF (AstroAI)
15pF reading "no, unknown or damaged part" (TC1) / 0.00nF (AstroAI)

 

[Robert]

This is what I use for measuring capacitors. It handles low pF values without any issues.
Semme M6013 LCD High Precision Capacitor Meter

For what it's worth, I have Fluke meters ranging from $40 - $1800 and none of them are suited for low value capacitors.

 

[MichaelW]

@PedalPCB Robert, is the Peak Atlas DCA55 worth getting? I've seen it mentioned here a few times. I have 2 Mega328 based units, one I built and one I bought (LCR-T7) and neither are really very consistent in reading NPN or MOS transistors. Like it takes 5-6 attempts before it will return an HFe value. (They do read low capacitance caps though).

 

[blackhatboojum]

I second @PedalPCB. I have a crazy expensive Fluke that I use for work, and I have it calibrated annually at my company’s R&D lab. Even still, it’s not really suited to measure small value caps. I also have the exact same AstroAI you have and it’s within 1% tolerance of my annually calibrated Fluke on most components I measure. Personally, I wouldn’t waste the money on an expensive fluke for things like pedal building. If you’re doing a job where life or death depends on that multimeter… yeah, go with the industry standard and buy a fluke. Otherwise, buy that $50 component tester @PedalPCB listed and continue building guitar noise makers .

 

[fig]

LCR45 specs...

 

[DAJE]

@PedalPCB Robert, is the Peak Atlas DCA55 worth getting? I've seen it mentioned here a few times. I have 2 Mega328 based units, one I built and one I bought (LCR-T7) and neither are really very consistent in reading NPN or MOS transistors. Like it takes 5-6 attempts before it will return an HFe value. (They do read low capacitance caps though).

Peak Atlases are not for measuring capacitors.

EDIT: The DCs aren't, they do make cap testers but that's a different device.

 

[DAJE]

My method of measuring caps that are too small for my tester: get 100 pF cap and test. Let's say it reads 90 pF. Then add the smaller cap in parallel. Let's say it reads 135 pF. So, 135 - 90 = 45 pF. Approximate, but that's as close as you need.

 

[pcb rookie]

Thank you all or your input!