[sdiy] Circuit thermometer / temperature measurement

[Ullrich Peter]

Hi!

Another more sophisticated temperature measurement solution I use (maybe an overkill for some people):

For the temperature measurement on multiple points inside gadgets and PCBs I designed small I2C temperature sensor PCBs (16.5x15.2mm, the other 15x15mm) and an Arduino shield with an I2C multiplexer so that I can connect up to 64 sensors to one Arduino. My software scans all available devices on the bus at startup and reads all sensors once a second or at a configurable rate. The results are output in comma delimited format on the serial USB interface so that a terminal with logging mode can capture these data. I use Excel data import for further analyses.

I have one sensor board version with the MCP98243 temperature sensors that works from -40...+125°C, PCB size 16.5x15.2mm
http://ww1.microchip.com/downloads/en/DeviceDoc/22153c.pdf

and another version that uses the DS1631A thermostat chip, PCB size 15x15mm
http://datasheets.maximintegrated.com/en/ds/DS1631-DS1731.pdf
as this chip works from -55...+125°C (thos was nice as I had to design for the Russian climate zone...)

The Arduino shield is a shield that can work with 3V3 or 5V (jumper) Arduino boards and uses the I2C multiplexer TCA9548A.
http://www.ti.com/lit/ds/symlink/tca9548a.pdf
The eight I2C interfaces can be switched between 3V3 and 5V in groups of 4 interfaces as the multiplexer also support I2C level shifting.

Each interface can control up to 8 I2C temperature sensor boards (due to the 8 possible I2C addresses per Chip) so I can connect 64 sensors in total.
As I only have 20 sensor PCBs I only tested with up to 20 sensors, spread over all 8 ports.

I use industrial double sided sticker tape from 3M or Tesa to glue the sensors onto the interesting chips or housing parts.
http://www.tesa.com/industry/electronics/assortment_overview/pet_tapes/pet/tesa_4965,i.html

At the moment I have no further information on that, but I could make a webpage or PDF for it (including photos) if there would be enough interest.

Ciao
Peter

http://www.ullrich.at.tt        (My homepage)
http://synpro.heimat.eu/datadial.htm    (Synth addon)
http://rc100-usb.at.tt/     (Roland sampler tool)


-----Ursprüngliche Nachricht-----
Von: synth-diy-bounces at dropmix.xs4all.nl [mailto:synth-diy-bounces at dropmix.xs4all.nl] Im Auftrag von Michael Zacherl
Gesendet: Mittwoch, 18. Februar 2015 12:29
An: Synth DIY
Betreff: Re: [sdiy] Circuit thermometer / temperature measurement

I have a faint picture in my mind where Kent Spong used a pistol-shaped laser thermometer to measure the temperature of chips to track down the faulty one. 
In the caption he claimed it's quite accurate. Price was in the 30UKP range, IIRC.
But then again it's still just the surface temperature that's measured.
m.

On 17.Feb 2015, at 19:46 , Justin Owen <juzowen at gmail.com> wrote:

> Hello,
> 
> Anyone recommend a reasonable thermometer for measuring the operating temperature of PCBs and surface mount parts in-circuit?
> 
> I recently bought  a fairly cheap (<5.00) pen type food thermometer but a) for accurate readings it needs to be actually stuck in the food - which isn't entirely convenient for PCB parts and b) even immersed in liquids it's very slow to hit the required reading.
> 
> Any thoughts?


--
http://mz.klingt.org

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