PORTABLE COMBINED CONSTANT CURRENT SOURCE AND VOLTMETER
Jandel Engineering
Limited
HM21 Test Unit
Jandel Engineering offers the HM21 Test Unit for use in making four point
probe measurements. The HM21 has six constant current settings between
100nA and 10mA, and can be used to measure voltages from 0.01mV to
1250mV.
The quoted measurement range of the HM21 is from 1 ohm/square to 10
Megohms/square (sheet resistance), from 0.01 ohm.cm to 10 Kohm.cm (bulk
resistivity).*
Measurements can be displayed as mV values or directly in sheet resistance
values. Up to 50 readings can be stored in onboard non-volatile memory for
downloading to a PC using the free software included. The software can also
be used to operate the unit directly from a PC, and to output results as sheet
resistance, bulk resistivity, or ‘bulk resistivity for wafer’ values.
The HM21 enables current to be passed in a forward and reverse direction to
verify good contacts and measurements.
Overall accuracy is 0.5%, highest accuracy is in the mid-range of measure-
ments.
Connection to a computer can be made via USB connection, and the unit
can be operated standalone, via a graphical interface in the free software
provided, or by computer keyboard commands.
The HM21 can be powered using the supplied adapter or using four size AA
rechargeable batteries (supplied).
Jandel Engineering
Limited
Grand Union House
Leighton Road
Leighton Buzzard
Beds.
LU7 1LA
Phone: +44 (0)1525 378554
Fax: +44 (0)1525 381945
E-mail: [email protected]
Web: www.jandel.com
*
measurements outside this range are possible depending on sample type and possible reduced accuracy
