such as "±1% of reading +2 counts", reflecting the different sources of error in the instrument. Analog Analog meters are older designs, but despite being technically surpassed by digital meters with bar graphs, may still be preferred by engineers and troubleshooters. One reason given is that analog meters are more sensitive (or responsive) to changes in the circuit that is being measured. A digital multimeter samples the quantity being measured over time, and then displays it. Analog multimeters continuously read the test value. If there are slight changes in readings, the needle of an analog multimeter will attempt to track it, as opposed to the digital meter having to wait until the next sample, giving delays between each discontinuous reading (plus the digital meter may additionally require settling time to converge on the value). The digital display value as opposed to an analog display is subjectively more difficult to read. This continuous tracking feature becomes important when testing capacitors or coils, for example. A properly functioning capacitor should allow current to flow when voltage is applied, then the current slowly decreases to zero and this "signature" is easy to see on an analog multimeter but not on a digital multimeter. This is similar when testing a coil, except the current starts low and increases. Resistance measurements on an analog meter, in particular, can be of low precision due to the typical resistance measurement circuit which compresses the scale heavily at the higher resistance values. Inexpensive analog meters may have only a single resistance scale, seriously restricting the range of precise measurements. Typically, an analog meter will have a panel adjustment to set the zero-ohms calibration of the meter, to compensate for the varying voltage of the meter battery, and the resistance of the meter's test leads. Accuracy Digital multimeters generally take measurements with accuracy superior to their analog counterparts. Standard analog multimeters measure with typically ±3% accuracy, though instruments of higher accuracy are made. Standard portable digital multimeters are specified to have an accuracy of typically ±0.5% on the DC voltage ranges. Mainstream bench-top multimeters are available with specified accuracy of better than ±0.01%. Laboratory grade instruments can have accuracies of a few parts per million. Accuracy figures need to be interpreted with care. The accuracy of an analog instrument usually refers to full-scale deflection; a measurement of 30 V on the 100 V scale of a 3% meter is