Constantan Foil Modified Phenolic Resin Strain Gauge

1. Temp. Self-compensation
The hypostasis of Zero Output is the Potential Discrepancy of load cell between two output
terminals, and the Potential rest with the two Electric Bridge's resistance. The working Temp. of this
Electric Bridge's resistance change as well as the Zero Output of load cell, so this change about the
Zero Output of load cell called Zero Excursion(P).
Why the Electric Bridge's resistance will be change when the Temp. change? To strain gauge, it is
affected by its Heat Output. Heat Output is the strain gauge installed on the unfettered specimen, no
force, when the environmental Temp. Changes occur as a chance in its resistance. So the ideal of strain
gauge is the Heat Output approach Zero. This kind of strain gauge is Temp. Self-Compensation Strain
Gauge. But it is opposite speaking to Self-Compensation, this Temp. Self-Compensation Strain Gauge
also have Heat Output, just it is less than others.
We always change the materials of Sensitive Grids and change the Resistance Temp. Coefficients
by heat treatment make to make the Heat Output of strain gauge to approach Zero. We synthesize the
function relations which among Elastomer linear expansion coefficient, Foils linear expansion
coefficient, Resistance Temp. Coefficient and Temperature, with suitable heat treatment to produce
Self-Compensation strain gauge which linear expansion coefficient is 9,11,16,23.
Remark: "11" is suit for alloy steel, Martensite stainless steel, Precipitation
Hardening stainless steel etc.. "16" is suit for Austenitic Stainless Steel etc.. "23" is suit for
Aluminium alloy etc...
2.Creep Self-compensation
All metal will bring spring aftereffect, it says when the metal have force in its spring scope, it
distort and will not balance with its load at once, but a little later; after retract the force, it also will not
distort to original state at once, but a little later, it will become the same. So this will show by Positive

Creep that the output signal of load cell increase as the time increase. The output signal also will
Negative Creep, because the fundus and slice will slack (By stated stress will decreased by time), and
the value can be adjusted by change the configuration of Sensitive Grids, the materials of fundus and
produce technics. If the absolute value of Positive Creep is the same as the Negative Creep, then the
Creep of the load cell can Self-compensate to the best. Our company produces different Creep grade
strain gauge to satisfy our clients.

3.Elastic Modulus Self-compensation
In elastomer, elastic modulus decrease with the raise of the ambient Temp., and the output of the
load cell increase with the raise of the Temp. We adjust the heat treatment of Sensitive Grids to make
the Sensitive coefficient K decrease with the raise of the Temp., in order to counteract the increase
which brought by the elastic modulus decrease with the raise of the Temp. at last to achieve
Self-compensation,this strain gauge is called Elastic Modulus Self-compensation Strain Gauge. It
synthesize both effects about common strain gauge and Self-compensation elastic modulus, good
stability, low cost, high sensitivity, easy to produce and work, it is also suit for load cell which the
precision grade is 0.05 or mass production and low cost.

                           SELECT AND USE STRAIN GAUGE
There are many kinds of strain gauges with different performance. We should consider many
reasons to select and use the best strain gauge, first, we need to consider the terms of experiment and

SELECT AND USE STRAIN GAUGE
There are many kinds of strain gauges with different performance. We should consider many
reasons to select and use the best strain gauge, first, we need to consider the terms of experiment and

 Types to select We should select strain gauge according to the tested purpose, the materials and precision demands of the tested goods. For example, the sense organ of the load cell, then it need to select the Foil strain gauge which is small P and θ; If the sensitivity of the load cell needs to be large, then we should select Semiconductor strain gauge; we should select Foil strain gauge if we test the dynamic weighing.
 The fundus materials of the Sensitive Grids How to select the best and suitable Sensitive Grids or fundus materials? First, we should according to the environment, temperature, tested time and the ultimate straining, then we also need to consider the precision demand of the strain gauge, For example: In -30~+80 , you should choose ºC CuNi, NiCrFe or Phenolic strain gauge; And in 80~150 , the ºC n use Polyimide strain gauge is better. The resistance of strain gauge We consider and select the resistance of strain gauge according to the demands which the test equipment require to the resistance and sensitivity of strain gauge etc. For example, in the stress test, we usually use 120ohm train gauge to match the equipment; To the load cell, we use high resistance (350ohm, 500ohm, 1000 ohm even larger etc.) to improve its stability and sensitivity, sometimes we also consider the performance and the values and the function, we use high resistance strain gauge.