Products > Test Equipment
Hioki IM3570 LCR & Impedance Analyzer
KungFuJosh:
--- Quote from: mawyatt on September 01, 2024, 03:12:15 pm ---Can you tell if the Kelvin wire shields follow down the clip handles, or the unshielded blades like the Tonghui Kelvin Clips?
--- End quote ---
I can't tell. There's no way to peak inside without disassembling the clips. They're fully insulated for sure (see photo), which makes me want to believe they're fully shielded too. For the retail price, they sure as hell should be.
mawyatt:
--- Quote from: KungFuJosh on September 01, 2024, 03:20:06 pm ---
--- Quote from: mawyatt on September 01, 2024, 03:12:15 pm ---Can you tell if the Kelvin wire shields follow down the clip handles, or the unshielded blades like the Tonghui Kelvin Clips?
--- End quote ---
I can't tell. There's no way to peak inside without disassembling the clips. They're fully insulated for sure (see photo), which makes me want to believe they're fully shielded too. For the retail price, they sure as hell should be.
--- End quote ---
Setup the Kelvin Clips measuring a leaded 1~10pF Mica cap at 100KHz, then slide hand around on clips "H" handle and remove hand while watching readings. Do this test with the Tonghui and Hioki Kelvin Clips and note the effects of the hand around the clip "H" handles.
If the Hioki are significantly less sensitive to hand placement than the Tonghui, then likely the shields extend down the Clip handles. We know the Tonghui is sensitive as it has the connection blades unshielded extending up thru the Clip handles like the cheap Kelvin Clips you see everywhere.
These work fine at DC or very low frequencies, but not as frequency increases, and why we prefer the various other type fixtures available or by custom design/construction/modification.
Best,
KungFuJosh:
I can do that test with the Hioki, but the Tonghui is packed up to be sold.
The L2000 is rated DC to 8MHz, I sincerely doubt that it's not shielded in the clip handles. I just read the (attached) manual, and I never noticed the arrows for correction before. Oops.
mawyatt:
Hopefully they are shielded to the tip. Even coming from Hioki we wouldn't put much faith in Kelvin Clip measurements at 5MHz, much less 8MHz. Just too many almost uncontrollable variables at play :o
Do take note of the data sheet and how Hioki recommends the Short Compensation, so many folks don't pay attention to the actual Kelvin Tip Identification (all our Kelvin Clips have Identification on each Tip, Hc, Hp, Lc, Lp wether from OEM or we added such.
If you carefully trace the LCR Meter currents thru the Kelvin Clips you'll see why this is important for very low Z measurements and this applies to 4 wire DMM measurements as well.
Best,
KungFuJosh:
I feel like at some point I need to let you borrow them to put them through some tests. 😉
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