Are digital thermometers just wacky?

[testcase]

Is one of them a rectal thermometer? miley-shocked003:

[Bill in NC]

Consumer grade medical devices are not known for their precision.

Case-in-point all those $20 pulse-oximeters that have become popular recently...they're around +/-6% accurate...medical-grade versions start around ten times that, IIRC.

[neophyte]

Bill in NC wrote:
Consumer grade medical devices are not known for their precision.

Case-in-point all those $20 pulse-oximeters that have become popular recently...they're around +/-6% accurate...medical-grade versions start around ten times that, IIRC.

I think you meant "not known for their accuracy".

As Carnos pointed out, Accuracy denotes closeness to the truth...

In the case of digital measurements, precision denotes how finely you can measure. Consumer digital thermometers mostly have the same precision: xx.x degrees F (3 significant figures). Their accuracy depends on how well they were calibrated at the factory that made them.

Infrared thermometers all have lousy accuracy in my experience.

[Diana]

As others have stated, accuracy is a measure of how much the measurement deviates from the known true value. The closer the measurement is to the true value, the more accurate it is. Normally, we measure things in triplicate or more, so we take the average of those measurements. One measurement by itself doesn’t really tell you much, other than how close ONE measurement is to the true value. It’s total accuracy can still be way off, because if I measure it again and it’s way off I then have no way of knowing which one is closer to the truth. Thus, more measurements leads to a better estimation of how accurate any measurement may be.

You really cannot use precision as a term with only one measurement, as precision is a measurement of how closely the previous measurements (plural) agree with one another. It has nothing to do with the true value and strictly speaking you cannot use the two terms (accuracy and precision) interchangeably. Analytically speaking, a balance is understood to have a precision of +/- the last digit: a balance measuring one decimal point is +/- one decimal point; one that measures to four decimal points is still +/- that last decimal point, unless otherwise stated. A balance that measures four decimal points (0.0000) inherently will give a mass reading that will be better known than one that only gives three (or fewer) decimal points, and this is often advertised as a more “precise” balance. Precise used in this manner really muddies the waters, as it doesn’t really describe precision. You may know the value more precisely, but it doesn’t imply more precision.

Any balance can give measurements that are wildly off, irrespective of its stated precision. Thus, analytical balances are calibrated against a known standard prior to use. Such balances are sensitive and will drift due to atmospheric conditions and thus must be calibrated. Things you purchase for personal use are calibrated prior to shipment, and are quite often robust enough to not be affected by a lot. Additionally they are made from materials that are often unaffected normal conditions.

Diana

[RAMd®d]

Case-in-point all those $20 pulse-oximeters that have become popular recently...they're around +/-6% accurate...medical-grade versions start around ten times that, IIRC.


That's the problem with consumer grade instruments - having a lab grade standard level machine to which said consumer device can be calibrated.

But, I have an iHealth Air Pulse Oximeter which is spot on with three different Watches - OG Apple Watch, Series 2, and Series 5, all of which are reputed to be very accurate regarding pulse.

As to the O₂ measurement, I can only hope.

I'm still hoping there's no oximeter capability in the Series 6.

[NewtonMP2100]

....can you call Dr. Bombay.....????

[space-time]

I'm still hoping there's no oximeter capability in the Series 6.

Why are you hoping that?

[RAMd®d]

Why are you hoping that?


If the S6 has an oximeter that's as accurate as its heartbeat monitor, I'll have to get one.

I'll have had my S5 for less than a year.

[Racer X]

I think I saw that movie "The Wackiest Thermometer in the Army"

[N-OS X-tasy!]

Racer X wrote:
I think I saw that movie "The Wackiest Thermometer in the Army"

That's the one that starred Don Knotts, right?