How do you measure your coating?

[SM7UYJ]

I've been trying different coatings for my ESL's but have had no good way off knowing the "exact" surface resistance.
I have used the method with two coins and a multimeter and I also have a small testpanel to try how the coating works under real conditions.
The time has now come to make a more correct measuring device.
I hopefully will have the opportunity to buy an old Gigameter soon, but until it's on the work bench I would like to build my own DIY-version!

This is what I'm thinking:

1. Probe.





80x80mm Plexiglas with 80x17mm Copper strips 5mm thick.

Gives 1:1.78 W/L

2. DC PSU.

500 or 1000V low current PSU, LM317->NE555->IRF840->diod multipliers.

3. Multimeter. Known internal resistance 10M Ohm


Connect everything in series and measure the voltage over the multimeter.

Will this work, or is there a better/easier way to do it?

/R

[alexberg]

Originally Posted by SM7UYJ

I've been trying different coatings for my ESL's but have had no good way off knowing the "exact" surface resistance.
I have used the method with two coins and a multimeter and I also have a small testpanel to try how the coating works under real conditions.
The time has now come to make a more correct measuring device.
I hopefully will have the opportunity to buy an old Gigameter soon, but until it's on the work bench I would like to build my own DIY-version!

This is what I'm thinking:

1. Probe.

80x80mm Plexiglas with 80x17mm Copper strips 5mm thick.

Gives 1:1.78 W/L

2. DC PSU.

500 or 1000V low current PSU, LM317->NE555->IRF840->diod multipliers.

3. Multimeter. Known internal resistance 10M Ohm


Connect everything in series and measure the voltage over the multimeter.

Will this work, or is there a better/easier way to do it?

/R

Per suggestions from this forum frequenters I used simple stencil with slot about 1cm wide + Graphite 33 spray. Draw two strips on coated mylar about 10 cm long and 1 cm apart. Then measure resistance using voltmeter with known input resistance as ampermeter. Metal foil strips did not yeild reliable contacts
Alex

[kavermei]

SM7UYJ, I think what you say is good, put some 1kV DC across a piece of foil and measure the current. That's what I'd do.

Kenneth