We offer for a few years an exact
replacement of the well known UC2 and UC3 range of load cells, originally developped
by Gould-Statham® who finally decided to stop production in the early 80's.
There are multiple applications of this range of load cells, in medical reasearch
as well as in the field of industry.
- medical research (pharmacology)
- muscles contraction force measurement
- heart contractile force in small lab
- applying a known force to skin
- measuring uterine contractions
- weighing of organs in vivo
application examples :
- industrial research
- testing plastic pipes for hydrostatic pressure
- testing microswitches
- measuring dimensional changes of glass under pressure
- measuring spring tensions on satellites
- weighing fuel for engine test
- measuring micro leaks of fluids or gaz
- measuring deflexion of materials under load
Our supplier has renewed the UC2 and UC3 series by launching the GM2 (-30/+30 g)
and GM3 (0-60 g). These ones are built on an unbonded strain-sensitive filaments
technology which gives them an very high sensitivity together with excellent stability
in temperature. As an example, the temperature effect on span is less than 0.02%
per degree between -15°C and +65°C.
Thanks to its strain-sensitive filaments construction, the original strain gage,
it is easier to obtain a better thermal stability and avoid the designing problem
of a specific load cell body. On the opposite side, the production of such a cell
is far more complicated and requires specific workmanships : a platinium wire of
1/100 mm section has been devoted to be the sensible element. This kind of material
provides a good wire mechanical stability, is completely non-sensitive to solvents
and provides a excellent gage coeficient (capability to have a large resistance
variation depending on strain or elongations). In order to give the best response
possible, platinium wires have been assembled in a Wheastone bridge.
Each platinium wire is fixed on special plots. These plots need to be built in
a very good isolating material with also a very low expansion coeficient. For these
two reasons, saphir has been choosed.
In order to avoid friction problems, the exis of the load cell, on which is fixed
the touch pin, is totally held by two spring washers made of copper-beryllium.
This assembly, which can be considered as the first level of the load cell, is
protected by stops and transfers the applied force on the touch pin to the platinium
wires which convert it into a linear electrical signal.
Our supplier offers a wide range of analog or digital measurement electronics and
also a kit called UL5 which is built to convert a GM3 into an electronic balance,
being also able to amplify its sensitivity (see photo hereunder).