from the operational amplifier op110 is applied to the first electrode 111 of the reference capacitance c0 as a result the potential v2 present on the second electrode 103 of the capacitance to be measured c is applied to the first electrode 111 of the reference capacitance c0 during this step 251 the potential present on the second electrode 112 of the reference capacitance c0 is equal to the voltage e2 step 253 in which switch s2 is closed to transfer charge to the reference capacitance c0 from the capacitance to be measured c step 255 consisting in using the operational amplifier op130 to compare the voltage present on the second electrode 103 of the capacitance to be measured c with the reference voltage v1 naturally to do this the sequencer 140 will previously have replaced the earlier potential v2 by the potential v1 on the inverting input of the operational amplifier op130 and similarly it will previously have replaced the earlier potential v1 by the potential v2 on terminal 104 step 256 consisting in opening switch s2 if step 255 indicates that the potential on the second electrode 103 of the capacitance to be measured c remains greater than the voltage v1 and step 257 consisting in switching the voltage at the output 122 of the converter 120 from the first voltage e1 to the voltage e2 in fig4 step 258 symbolizes the end of one iteration 250 on each iteration 250 the potential on the capacitance to be measured c is reduced by consequently at the end of the.