Definition, Engineering and Sales
These balances have 4 decimal places or a ± 0.1 mg resolution. Lower resolution becomes precision and higher becomes micro.
ENCLOSURE
A draft shield comes standard to eliminate air turbulence effects. Some offer optional size chambers to fit all applications. Even counting scale use draft shields, but are not analytical.
ENGINEERING
Quality models are “oven baked” for 24 to 48 hours. All thermal stabilization data stored inside the balance. Detachable display from weighing module reduces electrical noise.
RELIABILITY
Some economy models lack EMI & RFI protection. Low quality components deliver reduced life time. Budget price amplifiers, ADC, micro controllers degrade response.
SENSORS
Balances use MFR (Magnetic Force Restoration) sensor. If it has a strain gauge based sensor or equivalent it becomes a scale. Balance is a function of the sensor and not the resolution.
REPEATABILITY
A good repeatability has the same o less the minimum resolution. Many show repeatability of ± 0.5 mg on a ± 0.1 mg!!!! It may operate as a great precision balance, but a bad analytical 0.1 mg.
TEST
Place a test mass softly 10 to 20 times on the pan. All readings must be the same or have little variation. Slow response or deviation from the ideal may be warning.
USE
Warm up the balance prior use and do not leave heavy samples on the pan. Static may produce inconsistent weighing readings. Ionizers may address static effects, but may present a health hazard.
REPAIR
Replacing overloaded sensors is not recommended. Repair warranty could be limited to 30 days, so be prepared. It is best to have it insured or business depreciated.
SALES
Market prefers square weighing pan over circular one. Even though the corners may introduce weighing errors. Mid-range market migrating to either performance or budget.
