At the National Institute of Metrological Research (INRIM) an evaluation of a commercial dual source high resistance bridge has been performed. Its two main measurement modes (single measurements and multiple measurements) have been investigated. The best settle time of a 10:1 measurement of high resistance ratio has been estimated to be about three times the time constant of the circuit involving the resistors. This constant, in turn, depends on the highest value resistor. By means of mathematical estimators, suitable numbers of the readings of the detector have been established in order to minimize noises. A compatibility test at 100 TΩ has shown that the best precision of the commercial bridge is achieved utilizing the multiple measurements mode with the auto update function. This mode also allows the characterization of a resistor as a function of the settle time. This characterization can be useful for the owner of the resistor who can request the laboratory to perform the calibration of the resistor with the settle time which is necessary for him.

The article considers the step and impulse response of second-order linear systems with a positive zero. A particular parameterization of the system equations is proposed which enables good assessment of the influence of its parameters on transients. Expressions missing in the literature are derived for step response parameters such as the values of undershoot, overshoot, time of inverse response, rise time and settling time, as well as of impulse response. Based on them, a precise time-domain approach to design feedforward, feedback and mixed feedback– feedforward control structures for nonminimum phase objects is presented that considers both setpoint tracking and disturbance rejection.