The system uses electrostatic force to excite mechanical oscillation around the wire fundamental harmonic resonance

The oscillation amplitude is sensed by measuring the capacitance variation in the wire-tube system

Changing the high voltage modulation frequency mechanical resonance curve

Fully operated by a PC LabVIEW program

WTMTim ing unit

&ADC /DAC R/W

Tim ing unit

C o ntro l

C PU

&

RS232 inte rfa c e

PC se ria l p o rt

Se nso rM DT 1 C o m p a ra to r

HV m o d ula to r HVPo we r sup p ly

Sc a le r 1

Sc a le r 2

Se nso rM DT 2 C o m p a ra to r

Sc a le r 1

Sc a le r 2

Se nso rM DT 15 C o m p a ra to r

HV m o d ula to rHV

Po we r sup p ly

Sc a le r 1

Sc a le r 2

Se nso rM DT 16 C o m p a ra to r

Sc a le r

Sc a le r 2

System

bus

1

HVM o d ula to r

HVM o d ula to r

HV OFF

HV ON

Measure = fout (HV OFF) – fout (HV ON)

WTM

internal view

Sensor and HV modulation connections

RS 232 and T sensor connections

WTM

Control

panel

Parameter

setting

section

Output

section