Assembly DS18B20 digital temperature sensors + waterpoof trick

[ArT]

In UTCOMP-3 and UTCOMP-PRO kit there are few (2 or 4) digital temperature sensors called DS18b20:

UTCOMP_ds18b20_temperature_sensor.jpg (25.39 KiB) Viewed 16543 times

These sensors have wide temperature range (-40...+125C), high accuracy (+/- 0,5C) and quick response so it is good choice for many purposes, such as: inside/outside temperature, intercooler in/out and sometimes engine cooling system (water), oil temperature etc.

This tutorial describes how to assembly and solder these sensors to make them waterproof or how to assembly them in engine block to measure e.g. engine/oil temperatures.

1. Sensor assembly - soldering and making it waterproof

In order to measure inside/outside temperature (and other, e.g. intercooler in/out) the easiest way is to solder wires directly to the sensor. You should use heat shrinks to make sensor wateproof. Here is short video tutorial:



In this solution big advantage is fast response for temperature changes.
You can also buy waterproof variant of these sensor where sensor is inside stainless steel tube:

ds18b20_waterproof.jpg (42.09 KiB) Viewed 16543 times

Advantage is fast and easy assembling. Such sensors are also very reliable.
Disadvantage is not so fast response for temperature changing.

2. Assembly sensor in engine block (e.g. for cooling or oil temperature)

In order to assembly DS18B20 as engine oil or cooling system temperature sensor, you will need sensor with thread.
Not so easy to find on the market, but there is quite smart and easy way to accomplish this. Please take a look at this tutorial described by one of UTCOMP's users.

You will need:

• DS18B20 sensor
• any other sensor with thread
• thermal glue

Drill hole inside the sensor (do not drill throught)...

01-oil-temperature-sensor-autogauge.jpg (87.54 KiB) Viewed 16543 times

02-ds18b20-with-npt-thread.jpg (115.01 KiB) Viewed 16543 times

.. and use thermal adhesive to assembly the sensor:

03-ds18b20-as-oil-temperature-sensor.jpg (125.52 KiB) Viewed 16543 times

3. Other solutions for temperature measurement

UTCOMP supports also analog temperature sensors (NTC type). These type of sensors are very commonly used in vehicles as stock sensors for oil/water temperature. All analog sensors require calibration (please take a look calibration tutorial) and have worse accuracy than digital sensors. You can find these sensor with higher temperature range, e.g. up to 150C or even up to 180C.

[Kaldek]

Hello Artur, I know this is a very old post but I just modified a 1/8 NPT sensor bung to glue in a DS18B20 into it and had a slightly different experience with the thermal adhesive.

I used a product called "STARS-922 heatsink compound" as it was the only thermally conductive glue I could find but it seemed to have odd cure behaviour in that it seems to take high temps (~70C) to properly cure, which meant it needed to be carefully installed and allowed to harden without the sensor falling out of the bung.

Is there any different thermal adhesive you know of that would be a better option? Your adhesive does look different to mine as it is shiny whereas the stuff I used has a sort of chalky appearance.

[ArT]

I've used AG TermoGlue, it needs about hour in room temperature, consisentcy is like hard silicone
https://www.tme.eu/pl/details/termoglue ... t-agt-116/

[Kaldek]

I've used AG TermoGlue, it needs about hour in room temperature, consisentcy is like hard silicone
https://www.tme.eu/pl/details/termoglue ... t-agt-116/

Interestingly that looks very similar to - and has the same specs as - the stuff I used.
I found an interesting article that appears to confirm this but they also mention that we could use a thermal epoxy (although these look to be harder to come by and more expensive. The sensor bungs definitely seem to use an epoxy glue to retain the NTC thermistor (basically potting compound).

http://epicbeardquest.blogspot.com/2015/07/revisiting-stars-922-and-other-stuff.html

I'll see how well the stuff I used holds up before committing to potting compound.