VIT Voltage / Current Sensor

Accurate high frequency measurements of high voltages and currents are difficult. The limited input range of instrumentation, such as A/D converters, is often incompatible with a wide dynamic range. Driving balanced or floating loads complicates the issue further. It is very important to sense both voltage and current at the same point in order to get accurate phase information. Our VIT is inserted between the output of the power amplifier and the load.

This instrument is electrically equivalent to a wide band potential transformer and a shielded current transformer. It can tolerate 1000 V of common mode voltage up to 200 kHz, while maintaining the specified accuracies of magnitude and phase.

The outputs of the voltage and current channels are single ended and have a 50 ohm source resistance. These analog monitor voltages have the same waveform as the voltage and current under test. Their magnitudes are accurately proportional to the original magnitudes, and the phase shifts between the voltage and current channels are matched. Phase information will remain valid if the low level output cables are matched in length, termination, and characteristics. These monitor signals are available at an MS type connector on the rear, as well as at BNCs on the front panel.

VIT-10M-6

This is a single range version which uses differential voltage sense and average current sense. It produces a buffered, single ended low level output of 1 mV/V and 100 mV/A. All other specs are the same as the VIT-13. The unit is normally sold with 6 channels in the 3U (5.25 inch) high rack mounting package. Pricing for 3,4,5,or 6 channels is available.

VIT-13

This instrument has four levels of sensitivity of voltage and current which may be selected locally or via isolated TTL logic. In addition, it has a current transformer in both the high and low leg which may be selected by a front panel switch.

Specifications for VIT-13

Voltage Sensitivity	100 uV/V, 1 mV/V, 10 mV/V, 100 mV/V
Current Sensitivity	10 mV/A, 100 mV/A, 1 V/A, 10 V/A
VIT-14 only	100 V/A

Maximum input	5 kV RMS, 10 kV peak, 30 A RMS, 100 A peak

Maximum output	10 V peak (7 V RMS for sine waves) 100 mA

Output impedance	50 ohms

Accuracy:
100 Hz-50 kHz	1% of reading + 0.1% of full scale 1 deg of phase
40 Hz-200 kHz	2% of reading + 0.2% of full scale 2 deg of phase
10 Hz-500 kHz	5% of reading + 0.2% of full scale 5 deg of phase

Common mode	34 dB from 100 Hz to 100 kHz
rejection	24 dB from 10 Hz to 200 kHz

Primary Power	120/240 V 50/60 Hz 1 ph

Size (inches)	5.25 high Rack Mounting

Weight (pounds)	18

Photograph	VIT-10M-6	VIT-13

VIT Voltage / Current Sensor

VIT-10M-6

VIT-13

Specifications for VIT-13

Typical Amplitude Accuracy vs. Frequency