Ds18b20 vs ntc 100k

Projects General Guidance
1

Hi, I am doing on my egg incubator project and i need to read temperature with high accuracy and it also needs to be reliable. There is some EM interfearances.

So the question is, would you advise me to use ntc 100k or ds18b20.

I know that digital sensors are more resistant against EMI than analog.

Analog sensor can be read more often but i dont need to read it every second.

Analog sensors should be more acurate if calibrated carefully...

Correct me if I am wrong and please tell me what do you think. Thanks!

2

You’re facing EM interference. So the DS18B20 is the better option because digital sensors are much less affected by noise than analog sensors like NTCs.

1 Like
3

For this type of application ( egg incubator ), both sensors should do the job.

Both have the reading frequency and precision/accuracy you need.
And they are adequate for the temperature range.

I'd use the DS18B20. There is no need to calibrate, no complex analog circuits to interface, no data manipulation to get the PV(Process Variable ), and handling libraries are ready and available on the Net.

Cheers!

1 Like
4

Let's say that they are affected differently. It's always good to be aware of EMI when you wire your sensors.

1 Like
5

So i can use shielded cable to eliminate a part of emi, do i just connect it to gnd? And can i use shield as gnd of device too?

6

So if i use digital sensor, i can use shieldec cable,
If i use analog sensor, i can use shielded cable, the average temperature of lets say 10 readings and low pass filter (about 160Hz).

Please correct me if I am wrong.

7

And i need to read temperature every 5 seconds

8

I'm not any EMI-guru, but generally shielding is grounded at one end only/
You still need to use conductor for GND.

1 Like
9

Ok, thanks.

10

If i use low pass filter and i measure temerature every 5s and since I am measuring air temp in an egg incubator, may I use even lower frequency for filtering?

11

Why do you only choose 100K thermistor?
10K is much more common.

If you have a serious EMI problem then use a shielded twisted pair cable with with a differential/instrumentation amplifier.

1 Like
12

Hi, I ordered 10K thermistor.
If I understand correctly 10K is better for low temperature readings and in cases with EMI problems because current through circuit is higher?

Thanks

13

The suitability of a thermistor for a particular temperature range is basically a function of the B constant not the nominal resistance.

A properly designed circuit can be made to reduce EMI for any value of nominal resistance.

14

This topic was automatically closed 180 days after the last reply. New replies are no longer allowed.