# 85 C degrees after deploy sensor ds18b20 on RPI ZERO 2W
**URL:** https://discourse.nodered.org/t/85-c-degrees-after-deploy-sensor-ds18b20-on-rpi-zero-2w/88364
**Category:** General
**Created:** [29 May 2024 19:50 UTC](https://discourse.nodered.org/t/85-c-degrees-after-deploy-sensor-ds18b20-on-rpi-zero-2w/88364 "2024-05-29T19:50:13Z")
**Posts on this page:** 11
**Page:** 1
### Author:  [@devifast](https://discourse.nodered.org/u/devifast)
#### Post date: [29 May 2024 19:50 UTC](https://discourse.nodered.org/t/85-c-degrees-after-deploy-sensor-ds18b20-on-rpi-zero-2w/88364/1 "2024-05-29T19:50:13Z")
Many of my sensors show a temperature of 85 degrees during deploy, it is interesting that they do it for a different period of time. What caused this?
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### Author:  [@marcus-j-davies](https://discourse.nodered.org/u/marcus-j-davies)
#### Post date: [29 May 2024 20:00 UTC](https://discourse.nodered.org/t/85-c-degrees-after-deploy-sensor-ds18b20-on-rpi-zero-2w/88364/2 "2024-05-29T20:00:48Z")
Hi @devifast
A simple search :
> The power-on reset value of the temperature register is +85°C
This seems to indicate, this is the state the sensor is in after it has been reset, so a deploy will support this theory.
Source : [https://www.analog.com/media/en/technical-documentation/data-sheets/DS18B20.pdf](https://www.analog.com/media/en/technical-documentation/data-sheets/DS18B20.pdf)
I am not an electronics engineer, but its the best I can do.
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### Author:  [@ghayne](https://discourse.nodered.org/u/ghayne)
#### Post date: [29 May 2024 20:01 UTC](https://discourse.nodered.org/t/85-c-degrees-after-deploy-sensor-ds18b20-on-rpi-zero-2w/88364/3 "2024-05-29T20:01:00Z")
How did you wire them?
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### Author:  [@Colin](https://discourse.nodered.org/u/Colin)
#### Post date: [29 May 2024 21:10 UTC](https://discourse.nodered.org/t/85-c-degrees-after-deploy-sensor-ds18b20-on-rpi-zero-2w/88364/5 "2024-05-29T21:10:14Z")
As Marcus says, this indicates that the sensor has been reset. Just add a Switch node that blocks that value.
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### Author:  [@devifast](https://discourse.nodered.org/u/devifast)
#### Post date: [29 May 2024 22:11 UTC](https://discourse.nodered.org/t/85-c-degrees-after-deploy-sensor-ds18b20-on-rpi-zero-2w/88364/6 "2024-05-29T22:11:34Z")
Understood.
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### Author:  [@questuk](https://discourse.nodered.org/u/questuk)
#### Post date: [31 May 2024 07:43 UTC](https://discourse.nodered.org/t/85-c-degrees-after-deploy-sensor-ds18b20-on-rpi-zero-2w/88364/7 "2024-05-31T07:43:15Z")
Hi,
I am not sure what you have this attached to, to get the temperature value, but I hope you are waiting 750ms before the first reading of the data from the DS1820 ?
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### Author:  [@Colin](https://discourse.nodered.org/u/Colin)
#### Post date: [31 May 2024 09:44 UTC](https://discourse.nodered.org/t/85-c-degrees-after-deploy-sensor-ds18b20-on-rpi-zero-2w/88364/8 "2024-05-31T09:44:04Z")
Normally the 1-wire driver will cope with that.
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### Author:  [@devifast](https://discourse.nodered.org/u/devifast)
#### Post date: [22 June 2024 15:02 UTC](https://discourse.nodered.org/t/85-c-degrees-after-deploy-sensor-ds18b20-on-rpi-zero-2w/88364/9 "2024-06-22T15:02:46Z")
Thanks for the reply. The reading interval is 10 seconds. It will probably turn out to be a bad sensor.
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### Author:  [@ghayne](https://discourse.nodered.org/u/ghayne)
#### Post date: [22 June 2024 16:33 UTC](https://discourse.nodered.org/t/85-c-degrees-after-deploy-sensor-ds18b20-on-rpi-zero-2w/88364/10 "2024-06-22T16:33:17Z")
> [@devifast](#):
>
> It will probably turn out to be a bad sensor.
There are a LOT of cheap fake DS18b20's on offer unfortunately. Best to buy from a reputable dealer.
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### Author:  [@gerry](https://discourse.nodered.org/u/gerry)
#### Post date: [23 June 2024 02:03 UTC](https://discourse.nodered.org/t/85-c-degrees-after-deploy-sensor-ds18b20-on-rpi-zero-2w/88364/11 "2024-06-23T02:03:51Z")
That applies to lots of sensors, and devices not just 18b20
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### Author:  [@system](https://discourse.nodered.org/u/system)
#### Post date: [22 September 2024 20:39 UTC](https://discourse.nodered.org/t/85-c-degrees-after-deploy-sensor-ds18b20-on-rpi-zero-2w/88364/13 "2024-09-22T20:39:57Z")
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