Need a good 1 wire temperature sensor, there is a lot of information about the DS18B20, but I see nothing about it's quality or expected lifetime.

I was wondering which is the expected lifetime of a DS18B20?

I see them packed in probe fashion, need them like this. It seems that the company does not makes the chip pocket or probes themselves. Also there are bad reviews out there.

Are these thermometers serious to use at commercial level? If not, What other alternatives are out there for practical (maybe harsh?) use?

Would love to hear real world experiences...

These are not used widely for commercial systems, though that probably has more to do with their electrical characteristics and price than "reliability" per se (and, of course, compatibility with legacy systems).

Commercial HVAC systems generally use precious metal or base metal RTDs or thermistors. The elements in such sensors are less rugged than the semiconductor sensors, but the sensor manufacturers know what they are doing and make enormous quantities.

• Problems with the RTD is that they cannot be hooked directly to A/C Conveter. Perhaps there is a 1 wire thermometer for commercial use? – jacktrades Jul 5 '14 at 13:18
• The only semiconductor sensor I know of that has some degree of acceptance is the analog AD590. Quantities are high, so a few extra components are no big deal in HVAC, what matters is a reliable and very cheap system. An earlier (non "B") version of this particular part had serious issues with failures due to moisture, so this multinational company thoroughly screwed up, I'm afraid. – Spehro Pefhany Jul 5 '14 at 13:23

A company that has $4 Billion in assets, sales of$500 Million a year and is known for innovate products. As well on the product page for the device, medical instrumentation is one of the application areas, so reliability is implied. On the product page is also a link to reliability report with a mean time to failure of 25120 Years.

as far as harsh conditions go, never exceed the manufacturers recommendations.

• ok, but the manufacturer does not sells the probes directly. – jacktrades Jul 5 '14 at 0:20
• I think the point is that if you need to be super sure your sensor won't fail you better build something yourself or buy from some company that sells probe for a living. Amazon is not a good place where to look. – Vladimir Cravero Jul 5 '14 at 9:25

The MTBF is always based on the often false assumption, that there are no flaws in the user design and system build. All sources from external EMI effects on signal /noise ratio (SNR) and bit error rate (BER) require thorough EMI design, supply margin and noise and design verification tests (DVT)

This DVT must include all environmental stresses; climatic, mechanical, electrical susceptibility vs BER with DFT / DFM design review. If any is disregarded , it will be cause for more concern than MTBF of the chip.

Preferably, you will perform margin tests to BER for each stress test.