# Probes with protection against slipping?

There have been a number of times when troubleshooting something where I have caused more damage than was originally there when my probe would slip off a test point and short some things together. So my little brain started churning. What about test leads with a clear sheath that is spring loaded that covers the whole probe tip. This is always extended over the point. You press down on a test point and the plastic sheath pushes back until the metal probe tip comes in contact with the node. If you slip the plastic shoots back out to cover the tip and hopefully avoid a short. I am not sure how effective this would be but it might help. I did a search because I am sure someone thought of this and they have to out there somewhere but I haven't found anything just yet. I was going to try and make this but I don't really have the tooling. Has anyone seen something like this? If so can you point me to them, or am I missing the obvious design flaw? Thanks for the help, Russ

One variant of this is called "shrouded" probes.

These may have covers which are spring loaded and move away or the shroud may stay in position and need the tested point to intrude into the shroud end.

Just what the doctor ordered:

Fused probe bodies with 4mm contact tips. The tip are covered with a spring loaded sheath for added protection. Unscrew the tip to access and replace the fuse. Probe bodies are marked with the rating of the internal fuse.

From Cal Test electronics $14.93. Materials: Body: Polyamide (Nylon); Contact tip: Brass, Nickel Plt. Banana Contact: BeCu, Nickel Plt. Set available in red and black pair RS India grip probe. Made to grip a standard test point Extech TL810 Electrical Test Lead Kit, Double insulated with CAT III-1000V safety rating, Two 40" (1m) PVC lead extensions (1000V rating) with shrouded banana plugs on both ends, Two very sharp, extra long 0.3" (7mm) stainless steel tipped plug-on test probes, Two stainless steel flat tip test probes (0.6"/15mm long), Two plunger activated retractable jaw clips with a wide 0.75" (19mm) jaw opening (TL-810 TL 810)$45/set From

Double Insulated 4mm jack Conforms to BSEN61010 Fully Shrouded and insulated to HSE GS38 Suitable for all BS7671 BSEN61557 Alphatek - Metrel testers Other colours available . From

Same people

Double Insulated 4mm jack Conforms to BSEN61010 Fully Shrouded and insulated to HSE GS38

• Thank you, Those Cal Test Probes might do the job. I emailed them. I am not sure of their size. They look like regular sized DMM probes and if so I will buy them. – Russ Sep 9 '11 at 22:57
• I called Cal Test and the first probe that I thought might work I don't think will. They said it was mainly made for HVAC work and not for probing small things. I did order a few of the probes they recommend but they are not exactly what I had in mind. – Russ Sep 28 '11 at 21:45

I would recommend the following type of test clips:

Some of these have really fine tips,

which, when closed are almost completely retracted in the sheath. This is a lot better than the hook of a standard scope probe, which is too long and protrudes so that it can easily cause shorts. I find that these smaller ones don't get loose easily, and can be easily used for SMD pins. You may have to power off your devices before connecting the pins, as they may short to the neighboring pins when connecting. Once they're in place you can power up again.
This kind of clips is often used with logic analyzers where many clips have to be placed on several IC pins, often next to each other.

• The problem with the ones that grip around the pin is that on chips with real close pins, unless I power down I risk shorting between pins. – Russ Sep 9 '11 at 22:59
• I sometimes work on CRT monitors and constantly powering up and down when doing simple voltage checks isn't the fastest way to work and perhaps not the best for the monitor. – Russ Sep 9 '11 at 23:05

I have some nice small Hirschmann probes: