# Hydraulic pressure sensor for biological sample

I need to filtrate blood sample (About 2 ml). I have a tube (roughly 0,5 inches of internal diameter) attached to the filter cassette inlet. The cassette is plugged to vacuum pump. I would like to measure the pressure before filter. The easiest thing is to use some small sensor plus Arduino. What sensors can be used for that? Most common I see water piping sensor but its too big for my sistem.

Everything upper 1 kPa causes cells death. Pressure range must be rougly 0-750 Pa

• Product suggestions are against the rules of this site, so your question may be soon removed. Consider editing your question, perhaps asking for types or configurations of pressure sensors that may be useful in order to obtain accurate measurements for your setup and pressure range. BTW, a parametric search of the common world-wide electronic parts distributors will return hundreds of pressure sensor options. Try to specify what is really important to you. – Chris Knudsen Jun 11 at 20:37

## 1 Answer

Without any indication of the pressure range you are using, there are many possibilities such as oil pressure sensors used in cars.

You might need to consider calibrating such a sensor to make sure of the (non)linearity of the sensor's response then you can convert the readings to actual values either gauge or absolute as needed.

A bourdon gauge is also a possibility.

• nissan-modus.ru/wp-content/uploads/2019/11/… - Something like this would be too big in diameter (Car oil pressure sensor) farnell.com/datasheets/2291387.pdf - something like that seems to be better if its water resistant... – Hedgehog Jun 11 at 11:56
• So, make an adaptor to give a diameter suitable to what you need. – Solar Mike Jun 11 at 12:04
• I have 2-3 ml of blood sample. Car sensor is really too big. – Hedgehog Jun 11 at 12:27
• To measure the pressure in a small sample, use a capillary tube filled with an inert fluid such as silicone oil to transmit the pressure to your sensor. – Dave Tweed Jun 11 at 13:30