Product portfolio

SEMIKI measurement solution

SoC test system Vision Camera System PCB function tester Chip loading machine Repair measuring equipment

Electronic industry measuring machine

Multi-channel data logger Standard AC/DC programmable power supply High voltage meter Insulation resistance tester Ground resistance meter Leakage current meter ESD measuring device Electrical characteristics analysis equipment Production room equipment

Force and mechanical measuring equipment

Force measuring device clamp set Force sensor Force measuring base Torque wrench Force measuring system Decibel Material thickness gauge Vibration meter Gas meter Mechanical force gauge Electronic force gauge Torque measuring machine Speed machine Device for measuring material hardness Power screwdriver

Measuring equipment for mechanical industry

Standard measuring tools Thread check conditioner Profile measuring machine Coating thickness gauge Quality testing machine Magnetic measuring device Altitude measure

Temperature and humidity measuring device

Temperature and humidity meter Substance concentration measuring device Detachable probe thermometer Infrared thermometer, thermal camera Self-recording thermometer

Optical measuring equipment

Industrial cameras Measurement microscope Digital microscope Stereo microscope Beam intensity meter Colorimeter Endoscopy equipment

Lab equipment

Industrial scales Desktop scale Technical scales Analytical balance Industrial floor scales Hanna experimental measuring equipment Clean room equipment Spectroscopy and X-Ray equipment Simulation cabinets, drying cabinets, furnaces

KYOWA Strain Gages KFGS, SKS sensors measure material stress and strain

Producer: KYOWA

Category: Force sensor Tag: strain gauges

Stress gauges detect small dimensional changes (strain) in the form of electrical signals. By measuring the strain with a gauge attached to a material or structure, the strength or safety can be known. Therefore, stress gauges are used in many different industries including machinery, automobile, electrical, civil engineering, medical and food.
Stress gauges are also used as force, pressure, acceleration, vibration, displacement and torque transducers used for a variety of purposes including measurement and production line control.
Kyowa produced the first Japan-made stress gauge in 1951, and based on the abundant experience and technology accumulated over these years, we produce a wide range of high-performance, environmentally friendly stress gauges.

Principle of stress gauge
If the external tensile or compressive force increases or decreases, the resistance will increase or decrease proportionally. Suppose the initial resistance R changes with AR due to strain &: the following equation is established.
Types of stress gauges
Stress gauges are classified into foil stress gauges, wire stress gauges and semiconductor stress gauges etc.
Structure of stress gauge
The foil stress gauge has metal foil on a thin plastic insulation layer and the test leads are attached, as shown in Figure 2 below.
The stress gauge is bonded to the measuring object using a special adhesive. The deformation occurring at the measuring location is transmitted to the stress sensing element through the adhesive and the plastic base. For accurate measurement, the stress gauge and adhesive must be compatible with the measuring material and operating conditions such as temperature, etc.

KYOWA ELECTRONIC INSTRUMENTS -Japan

Strain Gages

A strain gage detects a minute dimensional change (strain) as an electric signal. By measuring strain with the gage bonded to a material or structure, the strength or safety will be known. Thus, the strain gage is used in various industries including machinery, automobile, electric, civil engineering, medical, and food.
The strain gage is also adopted as a sensing element of force, pressure, acceleration, vibration, displacement, and torque transducers used for various purposes including measurement and control of production lines.

Kyowa produced the first Japanese-made strain gages in 1951, and based on the abundant experience and technology accumulated for these years, we manufacture a variety of high-performance, environmentally friendly strain gages.

Principles of Strain Gages
If external tensile force or compressive force increases or decreases, the resistance proportionally increases or decreases. Suppose that original resistance R changes by AR because of strain &: the following equation is set up.
Types of Strain Gages
Types of strain gages are classified into foil strain gages, wire strain gages, and semiconductor strain gages, etc.

Structure of a Strain Gage
The foil strain gage has metal foil on the electric insulator of the thin resin, and gage leads attached
The strain gage is bonded to the measuring object with a dedicated adhesive. Strain occurring on the measuring site is transferred to the strain sensing element via adhesive and the resin base. For accurate measurement, the strain gage and adhesive should be compatible with the measuring material and operating conditions such as temperature, etc.

KYOWA Strain gage bonding installation procedure

Strain-gage Measurement Examples

KYOWA KFGS General-purpose Foil Strain Gages
New strain gages with the world highest level performance.

Materials Resistive element	CuNi alloy foil
Materials Base	Polyimide
Operating temperature in combination with major adhesives after curing (°C)	CC-33A: -196 to 120ºC CC-35: -10 to 120ºC CC-36: -30 to 100ºC EP-340: -55 to 150ºC PC-600: -196 to 150ºC
Operating temperature in combination with major leadwire cables (°C)	Polyester-coated copper wire: -196 to 150ºC Vinyl-coated flat cable (L-6, L-7): -10 to 80ºC Mid-temperature cable (L-11, L-12): -100 to 150ºC
Self-temperature-compensation (°C)	10 to 100ºC
Applicable linear expansion coefficients (×10-6/℃)	5, 11, 16, 23, 27
Strain limits at normal temp. (approx. %)	5.0
Fatigue lives at normal temperature. (times)	1.2×107 (±1500μm/m)

Relative images

Pic.: KYOWA strain gauge KFGS series at Semiki's warehouse

When ordering, specify the model of the strain gage and the code of the lead-wire cable with a space in between.

Eg
KFGS-5-120-C1-11 With 2 polyester-coated copper wires 15 cm long
→KFGS-5-120-C1-11 N15C2

KFGS-5-120-C1-11 With a vinyl-coated ﬂat 2-wire cable 5 m long
→KFGS-5-120-C1-11 L5M2R

KFGS-5-120-D17-11 With a vinyl-coated ﬂat 3-wire cable 5 m long
→KFGS-5-120-D17-11 L5M3S

KFGS-5-120-C1-11 With a mid-temperature 3-wire cable 5 m long
→KFGS-5-120-C1-11 R5M3

KFGS-5-120-D17-11 With a mid-temperature 2-wire cable 5 m long
→KFGS-5-120-D17-11 R5M2

If no lead-wire cable code is suffixed, the gage is delivered with gage leads only.
(Silver-covered copper wires 25 mm long)

How to bond KYOWA KFRS miniature strain gages on a PCB

KYOWA KC Wire Strain Gages

Featuring a longer gage length, the KC series gages are wire strain gages suitable for mean strain measurement of concrete under test. Usually, a model with the gage length over 3 times longer than the maximum diameter of the aggregate (gravel, sand, etc.) is selected for the purpose.

When ordering, suffix the lead-wire cable code to the model number with a space in between.

Eg
For the gage with a vinyl-coated flat 2-wire cable 5 m long
→ KC-120-120-A1-11 L5M2R

If no lead-wire cable code is suffixed, the gage is delivered with gage leads only.
(Silver-covered copper wires 30 mm long)