The Jandel HM21
The Jandel HM21 is a portable meter designed for use with a four point probe to
make resistivity measurements. For successful measurements the HM21 supplies a
constant current and displays either the resultant voltage or the sheet resistance in
ohms/square depending which function has been chosen.
Unpacking
When you unpack the HM21 you should find:
1. A power lead incorporating a 9V AC adapter
2. A set of four AA rechargeable batteries
3. A 100 ohm test resistor
4. A Jandel HM21
Getting to know the HM21
On the HM21 you will find the display:
(A typical reading on the HM21)
and there are also 9 buttons…
When pressed the ‘FWD’ button allows current flow in a ‘forward’
direction
