|Speedy Builder5||24/03/2019 07:14:56|
|1717 forum posts|
Can anyone tell me if there are low cost temperature probes with readouts about. I am looking to measure car cylinder head, carburettor and fuel temperature of my Austin 7 whilst driving under certain conditions. I have tried to get some "1 wire" temp sensors(18B20s) to work over the I2C bus of a BBC MicroBit micro computer, but fear it has defeated me, so looking for something which already exists. Temp range would be from -5 to 140 deg C and the distance from the probe to the readout about 1 metre.
Plenty of examples with the Arduino micro, but not for the Microbit ! - Perhaps I should change micro computers !
|Paul Lousick||24/03/2019 07:53:16|
|1048 forum posts|
Temperature probes are available for use with a multi-meter at reasonable prices. (electronic store, ebay, etc). I think they work by measuring the change in resistance of the sensor as temperature changes. Some multi-meters have a temperature setting on their display.
Another option is one of the hand held laser temperature guns. (Cheap as chips on ebay). Dis-assemble and use the internal parts with longer wires. Or operate it remotely with a lever or cable system. They have a hold feature that stores the temperature reading.
Edited By Paul Lousick on 24/03/2019 07:57:02
|John Paton 1||24/03/2019 08:11:31|
|141 forum posts|
Are you looking for two or three K type thermocouples and a data logger to run them simultaneously?
there are a number of cheap single channel meters that you can plug a thermocouple into but you might do better with a data logger if needing several channels.
|Adam Mara||24/03/2019 08:15:04|
|66 forum posts|
Have a lok at 'JAGETRADE Garden Tools -50~110 °c DC 12v Digital LED Thermometer Car Temperature Monitor Panel Meter Blu' it may be the answer if you don't want to log results. I have a couple of similar Inkbird units that have proved very reliable.
|Brian Oldford||24/03/2019 08:24:15|
490 forum posts
This youtube video by Ralph Bacon may be helpful.
Welcome to the Arduino world.
|Jeff Dayman||24/03/2019 09:00:44|
|1472 forum posts|
Something like the units at link below might work. They list for $27 each on Digikey.ca . May be cheaper from Asia, probably made there.
|Jeff Dayman||24/03/2019 09:03:45|
|1472 forum posts|
accidental double post - sorry
Edited By Jeff Dayman on 24/03/2019 09:04:28
|Nick Clarke 3||24/03/2019 09:22:45|
216 forum posts
I bought one of these a couple of months ago - OWON B35T+ Datalogger true RMS Multimeter Temperature Tester Bluetooth 4.0 BT - eBay 223443667199 - 44GBP at present
As well as being a multimeter it comes with a temperature probe (thermocouple) but I also bought a K type thermocouple probe to use with liquids eBay 272654971464 - 3GBP
It will log a series of readings and store them internally or send them via Bluetooth to a computer, tablet or similar.
With many devices it will read out the reading as you take it - very useful if you are poking around in something - you don't need to look away. Works on my android phone and also on iPhone, if not others.
A satisfied customer!
Edited By Nick Clarke 3 on 24/03/2019 09:23:38
|Barrie Lever||24/03/2019 10:21:28|
|177 forum posts|
Dont make it complicated, loads of easy solutions out there.
Type 'K' is the most common thermocouple and can be read by a multitude of devices, be careful modifying the cable as you introduce cold junctions which can scew the readings.
Where are you going to be measuring the cylinder head temp. ? I doubt you will see 140 deg C measured externally, so that opens up your choices and lowers your costs.
With the second item shown, you might be able to make a hinged panel to swing the displays out of view when the car is at rest.
Just my thoughts.
|4140 forum posts|
The Arduino is a better bet for this sort of project. In this case "better" than the Microbit because it's well established and loads of libraries & tutorials have been written for it - including the 18B20!
Installing and learning the Arduino IDE, and then a smattering of 'C' programming is a bit intimidating, but if you want to have a go I'm happy to provide support, and there are others on the forum.
|Speedy Builder5||24/03/2019 11:10:21|
|1717 forum posts|
Wow, opened a hornets nest!! Thanks for all the replies. I have to admit that the Microbit areana leaves this sort of project a bit short, and may consider a change over to Arduino and in the short term go for three of the cheapo displays as well. Dave, Message sent and thanks - I may take you up if I go down the Arduino route.
|XD 351||25/03/2019 04:00:20|
1228 forum posts
Has the code and wiring to set up to 8 channels using the 18B20 sensor .
Edited By XD 351 on 25/03/2019 04:01:51
|Joseph Noci 1||25/03/2019 06:19:17|
|462 forum posts|
If you just want to get the reading job done, and not hack about, there are a number of inexpensive options -
an example - 4 channel handheld readout device that does all you wish..click the link...
If you want to hack - first a simple device , Type K input device - AD8495 - with analogue out to, eg, a multimeter ( or anything, Microbit included, that has A to D inputs to read a voltage) - nicely mounted on a breakout board so easy to use..
Or if you want to hack even more...Some serial IO devices (SPI).
Edited By Joseph Noci 1 on 25/03/2019 06:21:14
261 forum posts
Used a type k thermocouple connected to suitable multimeter on my Vauxhall.
Held the sensor in position required with tyewrap and run wire into car via door aperture to meter.
Not high tech but worked fine!
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