alpal
30-03-2025, 02:49 PM
Hi Everyone,
I spent all my working life mostly repairing or upgrading electronic devices
as a qualified electronics Technician / Technical Officer.
I usually worked on industrial and military products
which were designed to be repaired.
I noticed that many domestic products were not designed to be repaired
and I found an interesting example of the following medical product.
It's an OMRON Model MC-245 thermometer used for measuring by placing under the tongue.
It seemed to be faulty and I noticed that my other spare thermometer
OMRON model MC-341 had a battery lid/cover - but wasn't working.
I easily replaced the battery and now it seems to work OK.
However the MC-245 has no battery cover.
After consulting many YouTube videos I pulled it apart knowing
that I would break the Thermistor wires and damage the end piece.
I wanted to see what was inside.
The 2 Thermistor wires were deliberately too short to slide the
electronics containing the display etc out without breaking the 2 wires.
It must have been assembled at the factory in 2 halves and the
plastic along the whole length heat bonded so that you couldn't replace the battery.
Also notice from the picture the 4 White plastic posts are heat sealed
instead of screwed on with tiny screws which meant that
the 2 broken wires could not be lengthened and re-soldered on.
Also - I checked the NTC Thermistor out with my multi-meter.
It measured around 48K ohms when cold and slowly
went down to around 42K ohms when I placed my fingers on the tip.
Anyway - when you buy one of these thermometers make sure yours
has a battery cover. :)
cheers
Allan
I spent all my working life mostly repairing or upgrading electronic devices
as a qualified electronics Technician / Technical Officer.
I usually worked on industrial and military products
which were designed to be repaired.
I noticed that many domestic products were not designed to be repaired
and I found an interesting example of the following medical product.
It's an OMRON Model MC-245 thermometer used for measuring by placing under the tongue.
It seemed to be faulty and I noticed that my other spare thermometer
OMRON model MC-341 had a battery lid/cover - but wasn't working.
I easily replaced the battery and now it seems to work OK.
However the MC-245 has no battery cover.
After consulting many YouTube videos I pulled it apart knowing
that I would break the Thermistor wires and damage the end piece.
I wanted to see what was inside.
The 2 Thermistor wires were deliberately too short to slide the
electronics containing the display etc out without breaking the 2 wires.
It must have been assembled at the factory in 2 halves and the
plastic along the whole length heat bonded so that you couldn't replace the battery.
Also notice from the picture the 4 White plastic posts are heat sealed
instead of screwed on with tiny screws which meant that
the 2 broken wires could not be lengthened and re-soldered on.
Also - I checked the NTC Thermistor out with my multi-meter.
It measured around 48K ohms when cold and slowly
went down to around 42K ohms when I placed my fingers on the tip.
Anyway - when you buy one of these thermometers make sure yours
has a battery cover. :)
cheers
Allan