Insulin syringe logic probe

HollyMinkowski

This is one of those things you see and exclaim
"now why didn't I think of that"

While searching for info on turning the eZ430-F2013 USB dev tool
into a general TI430 device programmer I spied this thing.
It's a logic probe for sm chip pins that really keeps it's
grip and avoids all the awkward slipping you get when doing
something like this. I just have to rig up a few of these!
Here is an image from the site.

ElectricAye

That's interesting. Those needles are stainless steel. I wonder how they soldered them.

BradC

I did work experience in a hospital back when I was at school. A blister pack of bare hypodermic needles were standard issue in every tech's toolkit. We just popped a small croc clip on them. The real advantage of the needle is the tip is so sharp it very effectively penetrates any oxidisation or coating on the connection you are poking at. I had them in my toolbox for a while until my mother found them and completely freaked out. Useful stuff.

Come to think of it, I'm working in a hospital right now. Maybe I'll ask for some [noparse]:)[/noparse]

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"Are you suggesting coconuts migrate?"

John R.

Depending on where you live, various size needles are available at places like "Feet Farm", "Farm and Barn", etc. in the veterinary supply area (as in care for livestock).

You can also usually get packages of syringes from your local pharmacy if you tell them what you're using them for. I used to take this route for getting syringes that I used for solvent cements for use with plastic (styrene) models.

With stainless steel, you need to graduate to "brazing" (basically soldering over 450 C). I would also not discount that some needles are assembled with good old fashioned "press fit". There really isn't much pressure involved.

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John R.
Click here to see my Nomad Build Log

HollyMinkowski

I think I will wrap the wire tightly around the top of the needle
and apply some conductive wire glue to hold it there.

schill

Pomona (among others, I guess) makes nice sharp probes for multimeters and the like. Very fine, pointy, and spring loaded if you want. Probe on one end, banana plug on the other.

I have some, but I can't seem to find them on the web site. They have smaller-than-normal handles - a smaller diameter.

[noparse][[/noparse]Edit follows]
OK. I found them.

Pomona part numbers: 6341, 6342, 6275.

http://www.pomonaelectronics.com/pdf/d6341-6342-6375_100.pdf

Post Edited (schill) : 5/21/2010 8:27:34 PM GMT

Alan Bradford

Hi,

The Insulin needles are 30 guage.

Im not sure what the diameter is, but they bend very easily.
Also they get dull rapidly. After using one 4-5 times to inject insulin they start to hurt. Dull = Pain
They are designed for Subcutaneous Injection (Under the Skin).
30 Ga is so small you cannot feel them (most of the time) when you push them in.

Intervenious Needles are larger and sturdier.
They need to be to be inserted into an artery or vein.
These are more painful, and most injections we receive are this type.
Interveinous make better probes, but are harder to get as everyone will think you are an addict with a new excuse!! Im not sure how to get them.

I worked at a hospital 25 years ago and I have a few 20 ga needles. I use alligator clips to connect to the meter.
To prevent anyone from using them otherwise I spray painted them flourescent green and pink.

Good Luck



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Alan Bradford ·N1YMQ

Plasma Technologies
Canaan NH 03741
www.plasmatechnologies.com

kwinn

I have always carried a couple of syringes and needles in my tool kit for lubricating or cleaning small parts. I have also made probes using the needles. The most reliable method so far is to start as Holly suggested, by wrapping the wire around the needle a few times and then sliding a short piece of the brass tubing (available at hobby stores) over the wire and crimping it. Part of a regular crimp connector will also work. To complete the probe epoxy the assembly in an empty plastic pen body.

BTW, the needles can be resharpened with a whet stone when they get dull.

Leon

I use very sharp spring-loaded probes. More expensive than hypodermic needles but easier to obtain in the UK.

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Leon Heller
Amateur radio callsign: G1HSM

kwinn

Thereare other options to make your own probes. Sewing needles work really well. The eye of the needle can be used as the crimp connector for smaller gauge wires. Only problem I have had with them is corrosion.