The presentation is on load cell which is used in weighing system at various application area. It is to measure weight/ load in any aligned system.

1. PREPARED BY
UJJWAL KUMAR CHOUBEY
UJJWALCHOUBEY80@GMAIL.COM

2. LOAD CELL
A load cell is a type of transducer. It
converts a force such as tension,
compression, pressure, or torque into
an electrical signal. As the force
applied to the load cell increases, the
electrical signal changes
proportionally. It is very essential and
widely used throughout the globe in all
segments.

3. TYPES OF LOAD CELL
 Pneumatic load
cell
 Hydraulic load cell
 Strain gauge load
cell
 Capacitive load cell

4. PNEUMATIC LOAD CELL
This load cell works on pneumatic
pressure. It consists of air supply,
diaphragm, platform and pressure
gauge.
The air pressure is applied to one end of
the diaphragm attached with a platform.
The pressure gauge is attached to
measure the pressure inside the
chamber.
The deflection of the diaphragm due to
external force or weight affects the
pressure inside the chamber, which is
measured by gauge and converted into

5. HYDRAULIC LOAD CELL
The hydraulic load cell uses piston and
cylinder arrangement with the piston placed
in a thin elastic diaphragm.
The load cell is completely filled with oil or
any fluid. When the load is applied on the
piston, there is movement in piston and the
diaphragm results in an increase in oil/ fluid
pressure. This pressure is then transmitted
to a hydraulic pressure gauge. The gauge
senses the pressure and converts it to
electrical signals.

6. STRAIN GAUGE LOAD CELL
Strain gauge load cell is highly accurate and
cost-effective. It has a metal body to which
strain gauges are secured. The body is usually
made of aluminum, alloy steel, or stainless
steel which makes it very strong and minimum
elastic. When force is exerted on the load cell,
the spring element is slightly deformed, and
always returns to its original shape unless
overloaded. The resulting alteration in
resistance of the strain gauges is measured in
voltage. The change in voltage is proportional
to the force applied. Its working principle is
based on Wheatstone bridge theory.

7. WHEATSTONE BRIDGE
A Wheatstone bridge is a set of four
balanced resistors with a known applied
voltage.
Excitation voltage (Vex) is a known
constant and output voltage (Vo) is
variable depending on the shape of the
strain gauges.
If all resistors are balanced, meaning
R1/R2= R4/R3 then Vo= Zero
If the resistance in even one of the
resistors changes, then Vo will likewise
changing.

8. CAPACITIVE LOAD CELL
While strain gauge load cells use resistance to
change voltage and therefore measure weight,
capacitive load cells use changes in capacitance.
It is more accurate compare to strain gauge load
cell.
Two plates with opposing charges stand at small
distance. When a load is applied, it forces the
plates closer. Results in current flow between
the negative and positive charged plates to
establish equilibrium.
A charge is then stored between the plates,
creating capacitance. The measured voltage is

9. APPLICATION
Food and beverages industry
Chemical industry
Oil and gas industry
Material testing
Medical industry