Whenever you work with equipment that measures results (equipment that's more complicated than a tape measure, of course), you make that equipment go off its preferred measurements just a bit. It's kind of like wearing shoes that have had tied laces for months, and you've been slipping them on and off; eventually, the laces loosen up to the point where the shoes aren't really tied tightly anymore. With equipment, the measurements get a little farther off each time until you recalibrate the equipment. You need to put your equipment through minor calibration almost daily to ensure that it's operating within its acceptable range. However, that's not enough; you also need professional calibration.
Each measurement you need or product line you're trying to produce has tolerances. Maybe you need to measure 100 pounds of soil, but it's OK if the scale you have measures out between 99.95 and 100.05 pounds. The equipment needs to be properly calibrated so that whatever it measures out as 100 pounds is within that range. When you have small tolerances like that, you really need the equipment to be in top shape and calibrated exactly. A professional calibration company can do this for you.
One of the problems with calibration is that the procedure differs for every type of equipment. A water pressure gauge will need a different procedure than an audiometer, which will need a different calibration procedure than a scale. If you attempt to do all of the calibrations for all of your equipment, you could end up mistakenly calibrating something to the wrong figure or tolerance. Farm that job out to a professional company to ensure that your equipment is calibrated properly and that there are no mix-ups.
When you do the same task over and over and always have a good result, you can get a little laid-back about it all; that's human nature. But when you're dealing with calibration, you never want to loosen up a bit about the procedure or the results; you never want to see a number that's just barely within the acceptable range and say, "Eh, good enough." Occasionally sending equipment out to a calibration company (or having a tech come to your property to calibrate larger equipment) ensures that the mini-calibrations you've been doing have all been accurate.
In many cases, the manufacturer will handle calibration, but if the equipment is old or does not have calibration included in its service plan, you can go to a third-party company. Don't avoid having someone else try calibrating the equipment you've been using. Your company will only benefit from ensuring everything is working properly. For more information and assistance, contact a company like Nationwide Gage Calibration.