Are you sure the tips are secured properly? If not, that could cause weird measurement issues.
If you applied voltage via a non-discharged cap or something, you could certainly fry the tweezers.
I got myself a pair of ST42, during some quick tests with the included calibration board I noticed some oddities with the unit, especially in dealing with small value MLCCs. I wonder if anyone else can confirm this or if this is an issue specific to my unit. The firmware version is 1.5.3.
1. Normally when measuring caps the secondary value shown is Rs, which makes sense, however once measuring values < 1nF the display shows switches to Rp instead.
(Attachment Link) (Attachment Link) (Attachment Link)
Generally speaking, series equivalent circuit mode is used when measuring low-impedance elements (with an impedance of approximately 100Ω or less) such as high-capacity capacitors and low inductances, while parallel equivalent circuit mode is used when measuring high-impedance elements (with an impedance of approximately 10 kΩ or greater) such as low-capacitance capacitors and high-inductances.
2. The meter does not recognize small value caps in lower frequency modes. Particularly to measure a 10pF MLCC the measurement frequency needs to be at least 1 kHz, for 1pF at least 10 kHz is required.
(Attachment Link) (Attachment Link) (Attachment Link)
3. The battery charge indicator is off. The unit charges quite quickly up to 100% however, when I unplug it, it almost immediately looses one bar. The problem disappears when I leave it charging for a while longer even after it shows 100% charge status.
W.r.t. the meter displaying Rp instead of Rs I'm not so sure if that makes sense. The meter auto-detects that the DUT is a capacitor (if the proper frequency is selected), in this case I almost always want to know Rs not Rp. So I think it should keep Rs the default for caps unless manually configured otherwise.
Other cases where parallel measurements are preferred are when measuring very low values of capacitance, when making measurements on dielectric and magnetic materials, and, of course, when trying to determine the separate values of two components in parallel.
Apologies if this has been covered previously (some quick searches in the thread didn't come up with anything similar), but would it be possible to add a REL/delta/NULL function for the resistance measurement?
I am trying to measure resistance in the milliOhms range and, even after doing a Short calibration, the tweezers are still displaying some 20 or so milliOhms with the probes shorted.
Thanks!Hi giosif,
Thanks for your suggestion.
Yes, we have tried to make the short cal result in zero, but we did not have much motivation to finish this optimization.
Cause the 20milliOhms is the limitation of the tips contraction and ST42, and we have discussed one option is to use a "<30milliOhms" to replace the test result,
This way to show the result to users may be more reasonable.
Do you have many test cases that need a smaller range, which can be used for milliOhms measurement?
We are trying to design real four-wire measurement tips, but the user experience is not as good as the normal tips.
Hello ceut. You wrote: "But, as I plan to use it also to check some low R value (current shunt resistor)" I don't think any tweezers are a good choice for this.
Hello everyone,
One question I have about the ST42:
- What is the max range of Capacitor mesurement ?
In the Delfom review, no problem and fast with a 10000uF: https://youtu.be/13cBzn5Svuk?t=1507
But in the specifications https://shannontweezers.top/docs/specifications/
4999uF (which is very very low for a LCR meter.)
Example: checking an audio capacitor of 22000uF would be ok with the ST42 ?
Also, some of you has got some news from Shannon as no new post since July ?
Thanks
I had not used my Shannon Tweezers for a few weeks, and now find that they no longer measure correctly. When I press two tips together, the displayed resistance is 9 to 10 kOhm (in Auto mode). The displayed value is fluctuating by several 100 Ohm, and depends mildly on the selected measurement frequency and voltage. When set to 10 kHz measurement frequency, approx. 7 nF is read instead.
I have done the SelfCal, Open and Short calibration from the Measure > Calibration menu, but the readings have not changed significantly. Is there anything else I can try?
I would just email Shannon. I think you'll get a faster response that way.
I somewhat regret publishing our email address on the website, which resulted in too many spam emails. I thought this would only happen in China.
I would just email Shannon. I think you'll get a faster response that way.I somewhat regret publishing our email address on the website, which resulted in too many spam emails. I thought this would only happen in China.
If you want to find me quickly, sometimes it is faster to send me a private message on this forum, because this website will send me an email reminder with very obvious characteristics. I can know at a glance that my friends are looking for me
Hmm, $180+ now? Just when I finally decided to order one...
Hmm, $180+ now? Just when I finally decided to order one...
Depends which version you get. The test board or leather case cost more. Still a good value anyway.
I mean the price increased like 70% in the last couple of weeks since I was last contemplating making an order. Then it started at about $100-ish (and the website still says $109 for the early birds), now the cheapest option is $168.
Meh.
lol, you missed that boat. I was an early bird...2 years ago.
Production costs on everything went up...and what are you going to get that's better for the price? Or double the price?