Spring cleaning - how to test ESD coating on my drawers?

[jpyeron]

I remember reading:

• DIY or Homemade ESD control for storage bins
• ESD-ifying plastic containers with conductive paint

So I went and got some Licron Crystal spray. Now how do I test it?

I thought about buying a Surface Resistance Tester but the device assumes a large open area, not a small 1.75" wide drawer.

[ataradov]

I would try a regular multimeter with solder wick attached to the probes to better distribute contact area. You should be able to observe 10 MOhm, and 10 GOhm seems completely useless to me.

[Tomorokoshi]

That drawer looks like it's made out of polyethylene, so nominally very high resistivity. I made direct resistivity measurements on ABS (~2x10^15 ohms), which is also very high. The technique I had to use was specified in 60079-0, and it also shows up in other places. The basic idea:

1. Get a representative test sample. It could be the same material, or a material of known higher resistivity.

2. Use conductive paint to make two lines, 10 cm long, and 1 cm apart.

3. When dried, set up a power supply and ammeter to read the current. Note that while this test specifies up to 500V, you shouldn't need that because you are purposely making it conductive lower voltages should result in reasonable current readings. Measure for at least one minute.

4. The standard specifies that the surface shall be cleaned with distilled water, then isopropyl alcohol, then distilled water again. Also that it should be "conditioned" for 24 hours at less than 50% humidity.

5. The resistivity will then be 10 x V / I.

With multiple samples you could test:

A. Resistivity vs. number of coats.

B. Durability of coating vs. abrasion. Perhaps use the samples from test "A".

[jpyeron]

I would try a regular multimeter with solder wick attached to the probes to better distribute contact area. You should be able to observe 10 MOhm, and 10 GOhm seems completely useless to me.

My multimeter is not good a measuring 10 to 1,000 Meg Ohm ( should have thought of that first). Licron spray say between 1 and 1000 Megaohms.

That drawer looks like it's made out of polyethylene, so nominally very high resistivity. I made direct resistivity measurements on ABS (~2x10^15 ohms), which is also very high.

See mention of Licron spray in the original post.

The technique I had to use was specified in 60079-0, and it also shows up in other places. The basic idea:

1. Get a representative test sample. It could be the same material, or a material of known higher resistivity.

2. Use conductive paint to make two lines, 10 cm long, and 1 cm apart.

Plan on using actual drawer, after coating with Licron spray. This test approach has hope.

3. When dried, set up a power supply and ammeter to read the current. Note that while this test specifies up to 500V, you shouldn't need that because you are purposely making it conductive lower voltages should result in reasonable current readings. Measure for at least one minute.

At 100V and max spec resistance I should expect 0.0001 mA at min spec resistance 0.1 mA. I have 100V PS, measuring the current will be fun.