hexagon_v4
 
 

Strain gauges

Download
 
 
Tenzometr bez podložky
without support
 
 
 
Tenzometr s podložkou
with support
 
 

Calibration and fatigue life

The function of a semiconductor strain gauge essentially consists in a very considerable and accurate change in its electrical resistance with applied mechanical strain. Senzors with these elements give to all mechanisms the ability to respond sensitively to mechanic impulses. They are usually used for force, mass, pressure, torque, acceleration and deformation electric measurements. Read more

Properities

Technical merits of semiconductor as compared with wire and foil strain gauges:

  • 60x higher strain sensitivit yallowing measurement without amplifiers, with standard ohmmeters, voltmeters and oscilloscopes
  • 60x higher threshold sensitivity making possible measurement of strain in metals beginning ... Read more

Calibration and fatigue life

Our strain gauges are tested in accordance with procedures of U.S. NAS 942. Each manufactured gauge is cemented to a testing beam and subjected to gradual strain in the range of ±2.5x10 -3 [m/m] while electrical resistance is simultaneously measured. Strain gauges with a damaged active surface structure fail under tensile strain +2.5x10 -3 [m/m]. Gauges unimpaired by the tensile test are taken off the test beam and their temperature dependence of resistance is determined. The computer then calculates constants of the strain equation from the dependence of resistance on strain. Minimal tolerance of characteristics is achieved by measurements of each gauge and responsible selection. The dependence of strain sensitivity on temperature is determined for each type and statistically checked. Read more

Code designation and dimensions

Značení tenzometrů
At present, we have these types of strain gauges in stock: Type „Positive“, length 1.5mm, 3mm and 6mm, with gauge factor C1 = 120 - 150 and with electrical resistance 120 , 350 and 1000 Ohm. Of course, we are able to produce strain gauges with parameters according to customer's requirements.

We deliver semicoductor strain gauges in two sorts of tolerance at pack, specified by assurance of their tolerance characteristics. For dynamic measurement and stable temperatures are suitable strain gauges marked as N-sort. For static measurements, sensors and strain gauges for temperature fluctuation are suitable ones marked as T-sort.
Tolerance at pack (standard is 5 pieces) Tolerance of typ

N-sort T-sort N-sort T-sort
R0 - Electrical resistance of the free gauge
± 0.4% ± 0.25% ± 5% ± 3%
RB - Electrical resistance of the free gauge with support
± 1% ± 0.50% ± 10% ± 5%
C1 - (Gauge factor) ± 2% ± 2% ± 5%
± 5%
C2 ± 8% ± 8% according to contract according to contract
α - Temperature resistance coefficient of the free gauge ---± 0.02%/°C --- according to contract
Positiv limit static tensile strain 0.3% 0.3% 0.3% 0.3%