Abstract: Weighing apparatus including variable capacitance load sensing means, a capacitance detection circuit, an analog to digital convertor and microcomputer control means is automatically verified for accurate operation. The capacitance detection circuit is provided with a computer controlled verification switch by which the value of a parameter, such as resistance in an attenuation circuit, can be changed. Automatic verification of correct operation is obtained by periodically, with no weight on the scale, obtaining a first weight reading, operating the verification switch to change the parameter and obtaining a second weight reading. The difference between the two readings is a verification value and is compared to a stored verification value obtained in the same manner during calibration and stored for later use. If the difference between the obtained and stored verification values exceeds an allowable limit, the scale may be disabled from further weighing.