Finding affordable ISFET transistors for pH measurement

[Boltzman Oscillation]

TL;DR

I want to buy a lone ISFET but I cannot find any online.

I was looking into measuring the ph levels of a lake nearby where I live. I wanted to tie the experiment to my electronics coursework so I did some reasearch and found the wonder electronic that is the ISFET. Unfortunately, I cannot find anywhere to buy an ISFET transistor; I can easily find premade ph measuring tools that use an ISFET but they go for around $300. Are ISFETS new technology or am I looking at the wrong places?

 

[Borek]

They are not that new, no idea why they are difficult to buy - perhaps they are way too specialized. Not that I ever tried to buy them, but I haven't seen them either and I do search for strange sensors now and them.

I would go the glass pH probe way, they are cheaper and basically all they need is a high internal resistance voltmeter.

 

[Boltzman Oscillation]

They are not that new, no idea why they are difficult to buy - perhaps they are way too specialized. Not that I ever tried to buy them, but I haven't seen them either and I do search for strange sensors now and them.

I would go the glass pH probe way, they are cheaper and basically all they need is a high internal resistance voltmeter.

Sigh, I was just excited to work with this different type of transistor than what I am used to. Thanks for the advice.

 

[Borek]

Given a cheap chance to try them I would not hesitate. One doesn't get called Mr. pH for nothing

 

[Boltzman Oscillation]

Given a cheap chance to try them I would not hesitate. One doesn't get called Mr. pH for nothing

I'm not called Mr. PH

 

[Borek]

But I am ;)

 

[Baluncore]

ISFETs are hard to find because they are specialised.
Early Si₃N₄ ISFETs were unreliable.
http://microsens.ch/products/ISFET.htm
http://microsens.ch/products/pdf/MSFET_3330_Datasheet.pdf

 

[Boltzman Oscillation]

But I am ;)

:O