Forgive my ignorance but I've never found an answer to this question....In the spirit of independent confirmation/research replication, should chemists operating a different altitudes above sea level factor in their specific value of gravitational force when measuring the mass of substances via generic spring scales found in most labs? For example when measuring out 50g of NaCl needed for an experiment, would't a chemist working atop the Colorado Rockies using the exact same spring scale as a chemist working in New Orleans technically pour out a larger quantity of NaCl (that still reads 50g per scale) vs. the NOLA chemist due to a lower value of gravitational force?
Scales that measure to better than 1% need calibrating to local gravity which depends on latitude, and to a lesser extent, local geology. Due to the equatorial bulge, objects near the equator weigh 0.5% less than those at the poles
Electronic scales normally come with 2 masses, typically their full and half range, and a calibrate mode.
The radius of the Earth is so big, compared to differences of altitudes here in the surface, that $g$ doesn't vary much for everyday applications. So, mostly, it's ok to use the standard gravity. Precision experiments, however, may require finer calibration.
From Wikipedia: "an increase in altitude from sea level to 9,000 metres (30,000 ft) causes a weight decrease of about 0.29%."
I work in a lab where we have 6 analytical scales which all have strain gauges to determine the mass. We calibrate them once a day, but one one of them frequently self calibrates several times a day.
Analytical balances rarely are beam balances now since they require more maintenance and the weights and beam needed to be locked down if it was to be moved. They are probably more expensive to construct than strain gauge balances. To minimize the effect of strain on the beam, the weights were removed from the side the material was placed upon to keep the mass on the beam the same.