A selection (61) , is made of one from a plurality of available threshold voltages as the reference threshold voltage for use in the comparing operation.

This test reference threshold has a value offset past a designate demarcation threshold value Vi among the set by a predetermined margin.

A second level-crossing detector generates a second level-crossing detection signal when said second predetermined waveform crosses a voltage reference level a second time.

As the tip electrode is rotated, the impedance between it and a reference level is observed.

Unless otherwise specified by the Commission, the eligibility threshold established for each licensee shall remain the annual reference threshold in subsequent broadcast years.

Furthermore, a reference generator (8) produces the reference threshold value (VTH) according to the temperature and the supply voltage of the entire circuit.

An output voltage (VCAP) of the integrator is compared with a reference threshold value (VTH) in a comparator (7).

Unless otherwise indicated by the Commission, this eligibility threshold shall remain the annual base reference for subsequent broadcast years.

The second switch turns OFF when the second level-crossing detection signal indicates the second predetermined waveform crossed the voltage reference level a second time.

Said reference width is predetermined from a first lens (V7) in accordance with the ophthalmic prescription of the wearer and to a reference threshold value of blurriness (BR).

Based on the determined boundary value, a reference threshold used when the distance information is calculated is adjusted.

The standard deviation of the spectrum is determined and the system compares that standard deviation to a reference threshold of a non-turbulent return if the signal is above noise.

Said value (VLB) is compared with a reference threshold (S) to decide if the cell has to be sent or not.

Initially in the programming pass, the memory cells are verified relative to a test reference threshold value.

Threshold values (Vth) for other solvents are determined by Vth=Vtho×Ge from the reference threshold value (Vtho) of the specific solvent and the correction factor (Ge) serving as the apparatus constant.