Semi-Micro Balances

Semi-micro balances read to 0.01 mg, sitting between analytical balances and true microbalances, with capacities typically in the tens to low hundreds of grams.

Sartorius, Radwag, Ohaus, Precisa and Mettler Toledo cover this range. At this resolution the installation dominates the result. Air movement from a door or air conditioning outlet, vibration through the bench, a temperature gradient across the weighing chamber and static charge on a plastic vessel will each produce more error than the instrument specification. A heavy stable bench away from traffic, an ioniser for static-prone samples and adequate acclimatisation time are prerequisites rather than refinements. Internal calibration and a documented linearity figure are worth having.