DS18B20 vs RTD

[Ramdough]

I am building an electric brewery and can build an RTD circuit or use a ds18b20 type sensor.

What does everyone suggest? Do I really need the better option?

My KISS, low budget, it's good enough..... Brew colleague says just do the DS route.

Thanks

 

[doug293cz]

Depends on what else is in your system. If you have PID's, then PT100 RTD's are easy to use and accurate. If you are building around a RaspberryPi, Arduino, etc., then the DS18b20's would be easier.

Brew on

 

[BrunDog]

Like everything in life... It depends. What controller are you using? DS is easier to implement and lower cost on certain hardware like an Arduino. But if super high accuracy/linearity is your goal, then RTD is better with higher cost. It is much harder to implement on non-RTD ready or open source hardware. Like Arduino.

 

[Ramdough]

So, I plan to use an Arduino, but I already have a schematic for implementing an RTD circuit. I guess the question is, is it worth the added effort?

 

[BrunDog]

For brewing on an Arduino, no, I don't think it's worth it to make the driver circuit for RTD. The one wire is basically an out of the box solution.

One small disadvantage though, which I forgot to mention is you will need to build your own probes. Not a huge deal but I don't know if DS probes exist off the shelf where RTDs do in various configurations.

 

[Ramdough]

I bought a bunch of small thermo wells that would barely fit bare RTD sensors (that I already own) or the DS sensors. I already plan on doing a board layout for a bunch of my other circuits I need.

So I guess the work difference is there, but probably not horrible. The question is, are RTDs that much better and are the DS sensors not quite good enough? Would I even notice a difference or would the beer benefit from better sensors?

 

[BrunDog]

For beer brewing, the DS is plenty. Accurate to a half of a degree C, if I recall correctly. The only critical temp is mashing (145 - 160 degs F), where you would probably calibrate it anyway. You probably could not get your physical mash medium to hold that fine of a temp difference across it anyway, unless you aggressively recirculated and mixed the mash.

 

[thekraken]

I use DS18B20 in my RIMS tube. They work well, and easy to use. @BrunDog is correct, they are accurate to 0.5c (0.9 f) which I have to believe is good enough for beer. I really like the one-wire aspect too, I can have as many probes as I want on just one digital input pin, that also means I don't need a dozen xlr connectors to crowd my panel.

There are options for ready made probes for the ds18b20: http://www.amazon.com/gp/product/B00CHEZ250/ref=pd_lpo_sbs_dp_ss_1?pf_rd_p=1944687502&pf_rd_s=lpo-top-stripe-1&pf_rd_t=201&pf_rd_i=B008HODWBU&pf_rd_m=ATVPDKIKX0DER&pf_rd_r=180YNXG1BMRTSHRZVADY

https://datasheets.maximintegrated.com/en/ds/DS18B20.pdf

[Edit]
Full disclosure: I've never used an RTD with an arduino.