How does load cell work?

What is loadcell?

Load Cell is a device that converts force into electrical signal.

Strain gage based load cell is made of a specially engineered mechanical component called as an element. Four strain gauges are positioned precisely and bonded on to the element using a special adhesive. (strain gauge is a device that changes resistance when it is deformed or stressed).

How does a strain gauge sensor work?

The force-electrical signal conversion happens in two stages:

1. Force applied deforms the element which in turn deforms the strain gauges
2. Strain gauges converts the deformation to electrical signals

The strain gauges are wired in Wheatstone bridge configuration. The bridge is connected to a power supply unit and a signal conditioner through a 4-core cable. When an input voltage (10VDC) is applied to the bridge, the output is a voltage in the range of few millivolts.

The load cell output is proportional to the load applied to the element.

Wheatstone Bridge

What is sensitivity of load cell?

Basic specifications of a load cell-

• Capacity (kg)
• Full scale Output (mV)
• Sensitivity (mV/V)
• Excitation Voltage (VDC)
• Input resistance (ohms)
• Output resistance (ohms)

What is a load cell calibration?

Below are the commonly used standard values-

• Excitation voltage: 10V or 12V DC
• Full scale output: 10mV, 20mV and 30mV
• Load cell sensitivity: 1mV/V, 2mV/V and 3mV/V
• Input resistance: 350Ω and 700Ω or 1000Ω
• Output resistance: 350Ω and 700Ω or 1000Ω
• Kobastar loadcell cable color code:
• Excitation +  Red
• Excitation –   Black
• Signal +         Green
• Signal –          White

Load Cell Prices

The prices of Loadcells are determined by various factors such as the application, capacity of the selected product, desired precision, and many others. For instance, in a paint manufacturing company, a Load Cell to be used in a hazardous area should be ATEX certified and explosion-proof. In a supermarket setting, OIML certified Load Cells should be used. For cranes and elevators, Load Cells should comply with machine safety regulations and be CE certified. In the food industry, RoHS certified Load Cells are necessary. All these considerations significantly impact the cost of the product.

The use of loadcells is rapidly increasing in industry. In Turkey, they are manufactured under the brand Kobastar to meet the needs of Turkish industry, with the product range expanding every day.

To choose the right Load cell for your applications, you can browse our products on our website, engage in online communication, or receive support over the phone from our experienced sales engineers.