A monitoring device includes a filtering section that extracts and outputs at least one of a high frequency component or a low frequency component of a beam current received from a detection output section of an ion implantation device; and a computation section that computes at least one of a value corresponding to a content ratio of the high frequency component in the beam current, or a value corresponding to a content ratio of the low frequency component in the beam current.

A current quantity measuring method of multi-beams irradiates with a charged particle beam, amplifies an electric signal corresponding to multi-beams passed through a plurality of aperture holes of an aperture member having the plurality of aperture holes to form multi-beams by irradiation with the charged particle beam, receives the electric signal amplified in the minute current measurement unit and counting the number of electrons in the multi-beams, calculates a current quantity of the multi-beams passed through the plurality of aperture holes by using a product of the calculated number of electrons in the multi-beams and elementary charge, and corrects irradiation time of the charged particle beam of each of the plurality of aperture holes on the basis of the calculated current quantity.

Methods and apparatus for measuring the voltage of at least one conductor (121, 122, 123) of an electrical power cable (10) comprise providing a container (22) made from a conductive material around a portion of the cable and at least one electric field sensor (301, 302, 303, 304) between the container and the cable and bringing the container to a constant potential and measuring the electric field with a sensor. The voltage is determined by comparing the measured electric field with electric fields simulated for a plurality of configurations of punctual electric charges.

A closed and open contact method to predict a usable life of vacuum interrupters in the field can include using computer instructions in the data storage to instruct the processor to position a calculated amp or calculated pressure on an ionic or current versus pressure calibration curve for the installed vacuum interrupter and identify trend data from a library of trend data corresponding to the installed vacuum interrupter and to the calculated pressure or calculated amp of the installed vacuum interrupter; thereby determining the anticipated life expectancy.

A device for measuring current by means of integration, includes a first operational amplifier connected as an integrator, and a second operational amplifier connected as an original current generator which can compensate for leakage current in the circuit measurement state and reset the Q0 charge of the integration capacitor in the reset state.

A system for verifying the operation of RF generators and resulting pulse waveforms in semiconductor processes includes a process chamber, a profile sensor, an optical sensor and a controller. A process implemented by the controller of the system for verifying the operation of RF generators and resulting pulse waveforms in semiconductor processes includes generating a pulse profile of a pulse shape of an RF generator under test, selecting a stored, representative profile of an RF generator known to be operating correctly to compare to the profile generated for the RF generator for a same pulse mode, defining a quantitative metric/control limit to identify similarities and/or differences between pulses of same pulse modes between the generated profile of the RF generator and the stored profile, comparing the generated profile and the selected stored profile, and determining if the RF generator under test is operating properly based on the comparison.

A method for detecting the position of the mass center of a passing-through beam of electric charges in a duct, having a passage section with a plurality of detection faces directed thereto is presented. The method includes: arranging couples of detecting elements, so that each couple detects a space area divided into two half-areas by an intermediate plane between the detecting elements of the respective couple; obtaining, from each detecting element, a signal thereby produced representing the distance thereof from the mass center to be detected; comparing the signals produced by each detecting element, by obtaining a digital signal showing the greater proximity of the mass center to one of the detecting element of the couple; and composing the digital signals produced by the couples of detecting elements, by identifying the cross-section of the beam of electric charges to which the mass center of the beam electric charges belongs.

An ion detection current conversion circuit includes a conversion amplifier coupled with a conversion resistor assembly for converting an ion detection current produced by an ion detector into an ion detection voltage, the conversion resistor assembly comprising a resistor having a high resistance and a capacitive compensation element, and a compensation voltage circuit for deriving a compensation voltage from the ion detection voltage and feeding the compensation voltage to the capacitive compensation element, the compensation voltage circuit comprising a variable resistor for adjusting the compensation voltage.

Methods and apparatus for measuring current are provided. In one arrangement, a first charge amplifier integrates a current to be measured. A processing circuit filters an output from the first charge amplifier using a first low pass filter module and a second low pass filter module. A second charge amplifier integrates a current derived from the filtered output from the first charge amplifier. The apparatus is configured to reset the first charge amplifier at the start of each of a plurality of sensing frames. The processing circuit obtains at least a first sample of the output from the first charge amplifier in each sensing frame. The sampling of the first sample alternates from one sensing frame to the next sensing frame between sampling via the first low pass filter module and sampling via the second low pass filter module.

A conversion circuit is arranged for converting an ion detection current (i.sub.D) produced by an ion detector into an ion detection signal (P). The conversion circuit comprises: an input stage for converting the ion detection current (i.sub.D) into an ion detection voltage (V.sub.D), an output stage for converting the ion detection voltage into the detection signal (P), the output stage being arranged for drawing a first current dependent on the ion detection voltage, and a supplementary stage for providing a second current (i.sub.S) dependent on the ion detection voltage to the output stage.

The second current may be substantially equal to the first current.