Barometers were more popular before accurate television weather, the weather channel, and the internet. Back in the day,* the barometer was a state of the art tech gadget. Many of them were made of brass and designed to look impressive on your wall. Having one was a sign of affluence and tech savvy. And they were your best bet for being warned of sudden storms.
QCMs measure down to nano-gram masses, based on resonance, so they use the (inertial) mass.
I wonder if something could be done with NMR? If you can use it to determine the composition and quantity of a subject’s parts, you might be able to total the numbers up against known values for those substances and arrive at a mass value. Would be horrendously complicated though.
Mass spectroscopy works better -> you deflect an mass with known charge in a known electromagnetic field. Works very well for molecular masses of macromolecules.
Speak for yourself. I weigh everything in ounces and pounds.
An analytical balance (e.g. single pan instruments made by Mettler) measures weight. But if the balance is not moved between calibrations, then it can be assumed the acceleration due to gravity will not change between calibrations, and hence weight will be proportional to mass.
A little trivia for ya: when you measure the mass of something using an analytical (single pan) balance, you are not measuring the true mass of the specimen on the pan, no matter how expensive the balance is or how carefully it is calibrated. The digital display on the balance reports *conventional *mass. If the specimen you stick on the pan has a density close to 8 g/cm[sup]3[/sup], then conventional mass will be approximately equal to true mass. If the specimen you stick on the pan has a much higher or lower density than this value (e.g. 1 g/cm[sup]3[/sup]), then there will be significant error between conventional mass and true mass.
I assume that’s due to the buoyancy from the air? But 8 g/cc sounds like an awfully high value to use for standard density-- That’s denser than most metals, even. And most organic chemicals are relatively close to 1 g/cc, like water. Are analytical scales made for different purposes calibrated to different standard densities?
Most calibration standards have a density of 8 g/cc.
Yeah, I agree. A density of 8 seems very high. A quick search turns up the factoid that most reference weights are made of stainless steel, which has a density of just on 8, and that is why the definition is thus. Not so it will work out nicely for most objects, but so that the calibration process is easy.
Ninja’d 
Yep.
There have been cases where pharmaceutical companies have put chemicals on a (carefully calibrated) Mettler analytical balance, and made calculations assuming the balance was reporting the true mass.
They didn’t understand the balance precisely reported the conventional mass.
Oops.
Just to be realistic, the theoretical buoyancy correction for materials in the 1 g/cc range is about 100 ppm, or 0.01%. This is usually not a significant error, even in pharmaceutical applications, but it might make a difference when preparing standards. The error usually contributed by buoyancy effects in various environments is more like 0.1%. This, coincidentally, is the USP specification for accuracy in weighing (which is to say that no measurement of mass in a pharmaceutical laboratory or manufacturing plant should err by more than that). However, the USP normally disregards air buoyancy, and so do most labs in the industry.
A balance isn’t comparing masses, it’s comparing forces. It’s just that one factor of the force (g) is conveniently equal and non-zero in both cases. Try comparing your masses in the absence of gravity and see how far it gets you. 
My previous comment was based on a class I took at NIST’s Metrology Lab about 15 years ago. The instructor relayed a story on how a drug manufacturer was getting unexpected results on their process line. There was a big investigation, and a NIST scientist discovered the root cause: they were not performing a buoyancy correction when measuring mass. The instructor did not provide any more details.