At Swiss Medtech Expo 2021, our stand featured a column of liquid whose height was measured indirectly with a force sensor. We wanted to show how precisely you can determine the pressure in a tube if you enclose three quarters of its circumference and measure its curvature on the remaining quarter.
Used in Medical Devices
This principle of pressure measurement without changing or interrupting the hose path is used by many of our customers in medical devices. Peristaltic pumps, for example, can detect blockages in the infusion flow by the increase in pressure and trigger an alarm. In ophthalmic surgery devices, the irrigation fluid pressure is measured in a similar way.
Connected Directly to the Arduino
Technically, the demonstrator is very simple. The sensor used is of type KB-011-0300 and has an integrated signal amplifier. It is directly connected to a "Seeeduino Lotus" development board, which linearly transforms the signal and displays it on a bar graph. Power is supplied by a USB power bank.
Many Applications Possible
The measuring principle shown can be used wherever pressures in the millibar range are to be measured, but hygiene requirements prohibit the use of classic pressure sensors. For example, it could also be applied in the food industry or in household appliances such as coffee machines.