Preamplifers & Preacquisition Units
Power Diagnostix provides a complete line of modular preamplifiers for various testing applications. The most significant difference among the preamplifiers is the frequency range in which they detect partial discharge signals. Other features that distinguish one preamplifier from another are: options for transparency and on/off switching, unipolar vs. bipolar charge detection, and the possibiltiy of galvanic isolation in the test setup.
All of the Power Diagnostix external signal conditioning modules and preamplifiers are remote supplied and remote controlled through a simple coaxial signal cable (RG58). This technique allows placement of these units close to the sensor or signal source. Furthermore, as these modules act as impedance converter and line driver, the weak signal source, such as voltage divider or coupling impedance, is not loaded by the cable capacitance or impedance.
This technique also provides enhanced over-voltage protection. All preamplifiers of the RPA series can drive a 50 W cable up to 50 m long.
The RPA1 is the standard preamplifier for measurements in the low frequency range according to standards such as the IEC 60270. The RPA1D, RPA1E, RPA1F, and RPA1G are variations on the RPA1.
The RPA1D and RPA1G are suited to connect directly to ultra-sonic acoustic sensors. To simplify connection, the they provide selectable power supply for the sensor (15 V or 28 V DC).
The RPA1L and RPA1H are intended primarily for measurements on medium and high-voltage power cables using the ICMcompact.
The RPA2 is primarily for measuring the PD signal spectra found with rotating machines, while the RPA2B is used with capacitive sensors to monitor cables and cable accessories at a higher sensitivity.
The RPA4 is a preamplifier set with fiber optic transmission, offering outstanding isolation properties.
The RPA6 allows selecting one of three frequency ranges according to the particular application. The logarithmic RPA6 is mainly used with monitoring applications, and as a versatile preamplifier for noise gating.
The frequency converter unit FCU is an ultra-wide band preaquisition unit, covering 100 to 1800 MHz. It has a logarithmic output and is mainly used for GIS applications.
The UHF1 and UHF2 offer an amplification of 27 dB in the range from 200 MHz to 1 GHz resp. 300 MHz to 2 GHz, and are suitable for boosting weak signals from GIS sensors.
The HST1B is an impedance converter for the measurement of voltages. The input impedance is as high as 10 MΩ and ideal to measure the low-voltage wave from e.g. a voltage divider. The output is to be connected to the SYNC IN of the ICMsystem.
|RPA1||40 kHz–800 kHz||10 kΩ//50 pF||<200µV||40dB/dec||Yes||Standard preamplifier|
|RPA1D||40 kHz–800 kHz||10 kΩ//50 pF||<200µV||40dB/dec||Yes||Built-in sensor supply,
switchable (15/28 V)
|RPA1E||40 kHz–800 kHz||10 kΩ//50 pF||<200µV||40dB/dec||Yes||0/20 dB attenuation|
|RPA1F||40 kHz–800 kHz||10 kΩ//50 pF||<200µV||40dB/dec||Yes||For the AIAcompact only|
|RPA1G||40 kHz–800 kHz||10 kΩ//50 pF||<200µV||40dB/dec||Yes||Built-in sensor supply,
switchable (Off/15/28 V)
|RPA1H||40 kHz–20 MHz||1 kΩ//50 pF||<400µV||40dB/dec||Yes||Oil/paper cable, DSO|
|RPA1L||40 kHz–20 MHz||1 kΩ//50 pF||<200µV||40dB/dec||Yes||Cable, DSO|
|RPA2||2 MHz–20 MHz||50 Ω//50 pF||<800µV||40dB/dec||No||Online measurements on rotating machines|
|RPA2B||2 MHz–20 MHz||50 Ω//50 pF||<200µV||40dB/dec||No||Cable sensors|
|RPA3||200 MHz–1 GHz||50 Ω//50 pF||<300µV||40dB/dec||No||GIS sensors|
|RPA3D||50 MHz–400 MHz||50 Ω//50 pF||<300µV||40dB/dec||No||Nearfield detection|
|RPA3E||20 MHz–200 MHz||50 Ω//50 pF||<300µV||40dB/dec||No||Nearfield detection|
|RPA4||40 kHz–800 kHz||10 kΩ//50 pF||<200µV||40dB/dec||Yes||Fiber optic isolation|
|40 kHz–800 kHz||10 kΩ//50 pF||<200µV||40dB/dec||No||For gating, selectable frequency range, logarithmic output|
|FCU2||100 MHz–1.8 GHz||50 Ω//50 pF||<200µV||40dB/dec||No||Logarithmic output|
|FCU2A||1 GHz–2 GHz||50 Ω//50 pF||<200µV||40dB/dec||No||Logarithmic output|
|FCU2B||100 MHz–1 GHz||50 Ω//50 pF||<200µV||40dB/dec||No||Logarithmic output|
|FCU3||100 kHz–50 MHz||50 Ω//50 pF||<200µV||40dB/dec||No||Logarithmic output, GIS sensors|
|UHF1||200 MHz–1 GHz||50 Ω//50 pF||–||–||No||GIS, sensors|
|UHF2||300 MHz–2 GHz||50 Ω//50 pF||–||–||No||GIS, sensors|