# DS18b20 Thermometer chip unreliable

**URL:** <https://forum.xod.io/t/ds18b20-thermometer-chip-unreliable/4434>\
**Category:** Hardware Interfacing Questions\
**Created:** [September 17, 2020, 7:48pm UTC](https://forum.xod.io/t/ds18b20-thermometer-chip-unreliable/4434 "2020-09-17T19:48:55Z")\
**Posts on this page:** 5\
**Page:** 1

<div class="post-metadata">

**Author:** ![fusionfanatic](https://yyz1.discourse-cdn.com/flex027/user_avatar/forum.xod.io/fusionfanatic/32/2757_2.png) [@fusionfanatic](https://forum.xod.io/u/fusionfanatic)\
**Post date:** [September 17, 2020, 7:48pm UTC](https://forum.xod.io/t/ds18b20-thermometer-chip-unreliable/4434/1 "2020-09-17T19:48:55Z")

</div>

Has anyone else found the generic Thermometer probes al-la amazon or ebay to be very erratic in their readings? ranging wildly into the thousands to minus figures?

I have tested various probes and bought one on a board to test it thinking it may be to do with the resistors in circuit etc. Is it a part quality thing or are they just like that?

Charlie

---

<div class="post-metadata">

**Author:** ![wayland](https://yyz1.discourse-cdn.com/flex027/user_avatar/forum.xod.io/wayland/32/1590_2.png) [@wayland](https://forum.xod.io/u/wayland)\
**Post date:** [September 19, 2020, 8:59am UTC](https://forum.xod.io/t/ds18b20-thermometer-chip-unreliable/4434/2 "2020-09-19T08:59:29Z")

</div>

The following DS18B20 thermometers have worked without issue for me:

> **[5 pcs DS18b20 Waterproof Temperature Sensors Temperature Transducer:...](https://www.amazon.co.uk/gp/product/B01MDQO9C2/ref=ppx_od_dt_b_asin_title_s00?ie=UTF8&psc=1)**
>
> 5 pcs DS18b20 Waterproof Temperature Sensors Temperature Transducer: Amazon.co.uk: Car & Motorbike

I followed the wiring instructions provided here:

> **[Interfacing Multiple DS18B20 Digital Temperature Sensors with Arduino](https://lastminuteengineers.com/multiple-ds18b20-arduino-tutorial/)**
>
> Learn 2 Methods(by Index & by Address) to Interface Multiple DS18B20 Digital Temperature Sensors On Single Bus along with its Wiring & Arduino Code

---

<div class="post-metadata">

**Author:** ![unosoperator](https://yyz1.discourse-cdn.com/flex027/user_avatar/forum.xod.io/unosoperator/32/2678_2.png) [@unosoperator](https://forum.xod.io/u/unosoperator)\
**Post date:** [September 19, 2020, 1:21pm UTC](https://forum.xod.io/t/ds18b20-thermometer-chip-unreliable/4434/3 "2020-09-19T13:21:35Z")

</div>

@fusionfanatic I have one in TO-92 package, and works fine.

---

<div class="post-metadata">

**Author:** ![fusionfanatic](https://yyz1.discourse-cdn.com/flex027/user_avatar/forum.xod.io/fusionfanatic/32/2757_2.png) [@fusionfanatic](https://forum.xod.io/u/fusionfanatic)\
**Post date:** [September 24, 2020, 1:06pm UTC](https://forum.xod.io/t/ds18b20-thermometer-chip-unreliable/4434/4 "2020-09-24T13:06:13Z")

</div>

I am not sure what the issue is with my ones, I am buying the same ones as Wayland from Amazon, they all behave the same way. In some circumstances they are very reliable for a decent amount of time. I thought it could be due to use in water (they are supposed to be water proof) So I tried brand new ones, even with the resistor on a pre-made board.

I need to put more testing time isolated from the main project.

Charlie

---

<div class="post-metadata">

**Author:** ![system](https://canada1.discourse-cdn.com/flex027/uploads/xod/original/1X/eb7348baa04192c2ef932d1db54d44f09f8a7888.png) [@system](https://forum.xod.io/u/system)\
**Post date:** [October 24, 2020, 1:06pm UTC](https://forum.xod.io/t/ds18b20-thermometer-chip-unreliable/4434/5 "2020-10-24T13:06:14Z")

</div>

This topic was automatically closed 30 days after the last reply. New replies are no longer allowed.