hello everybody

i am searching for a transducer which can measure
pressure exerted by a person when he writes on a
paper. so first is there any transducer capable of
measuring that? if so please suggest where can i find
one please.

 

A pencil or pen with strain gages cemented to it should do that much. Or a coaxial arrangement with a solid state force gauge at the top measuring the force transmitted through an "ink refill" Google "silicon force guages" for vendors. There is also simply setting the paper on what amounts to a scale platform.

Regards

cww

 

Sir,

If you could bit clear with the things it will be useful to me. What type of strain gages do it need. have u worked with it pls respond as soon as possible.

SSBabu

 

Well, it's not the usual bending beam arrangement, but you'd still want pairs. Is this a test lash-up, a permanent instrument? Alas, strain gages are not a commodity item so your selection will depend on temperature range, substrate (what the pen barrel is made of) bonding system and a host of other considerations that are more or less particular to a manufacturer of strain gages. They would be happy to help you use their gages. There are far more choices today than when I was involved. If the engineering isn't practical for your situation, the coaxial idea would be somewhat simpler if a suitable force transducer can be found. You could even adapt a pen size gas spring and measure pressure. I'm happy to share ideas, but product development is kinda how I want to pay the bills. My gut feeling is that this shouldn't be very difficult. The micro silicon force stuff is beginning to appear and the pressure transducers are already commoditized. Picture a pen sized hydraulic cylinder with a pen refill attached to (inside?) the piston rod and a silicon pressure transducer fitted to the port end. This could be done with stuff I've seen cheap. Proof of concept could probably be kludged from an existing pen with a couple of O rings and some epoxy. Go hydraulic because a springy pen would feel funny. Or, I'll be happy to develop the "force pen" for you.

Regards

cww