OHAUS Defender D30BR, Service Manual

Page: 29 / 32

APPENDIX A GLOSSARY
APPENDIX A. GLOSSARY
Ohaus Load Cells contain a specification label on the Load Cell itself.
Compensated Temperature Range
The range of temperatures over which the output from the cell is compensated. If used
outside this range the output cannot be guaranteed to follow the specifications.
Environmental Protection
IP rating against moisture and dust, for example, IP 65.
Excitation
Voltage applied to the Exe+ and Exe– leads of the load cell.
Input Resistance
The resistance measured across Exe+ and Exe– with load cell disconnected and
no load.
Insulation Resistance
Normally measured at 50 V dc, this is the minimal resistance between the metal body of
the load cell and any of its electrical connections.
Mechanical Failure
The load at which the cell is likely to fail mechanically, that is, break or deform.
mV/V
Usually the output from a load cell will be approximately 0m V at zero load, though
typically there may be a small offset voltage at zero load. Over the full rated capacity of
the load cell, the mV output will change. The amount by which it changes depends upon
the resistance change in the cell and on the excitation voltage applied. Since the load
cell manufacturer does not know what excitation voltage will be applied to the cell, rather
than quote the V output over full range, they will quote the milli-Volt output per volt of
excitation, or in its short form, mv/V. Most Ohaus Indicators provide an excitation voltage
of 5 Volts dc.
Output Resistance
The resistance measured across S+ plus and S– with load cell disconnected and
no load.
Overload Capacity
The maximum load that can be applied without permanent damage. Loads in excess of
maximum capacity will cause damage to the load cell.
Rated Capacity
The maximum load over which the load cell will operate within its specifications.
Rated Output
The nominal mV/V output of the load cell.
Ultimate Capacity
This is a percentage setting, usually 300% of full capacity.
Zero Balance
The output of the load cell at no load, normally quoted as a percentage of full load. Also
known as zero offset.
Defender™ B & V Series Service Manual A-1 Ohaus Corporation www.ohaus.com