0
A proximitor is an electronic device that generates a radio frequency (RF) signal using an oscillator circuit. It also processes the RF signal to extract usable data using a demodulator circuit. A proximitor is often used in conjunction with a proximity probe to measure the displacement of a target surface.
What else can I help you with?
How Proximitor works?
by sunlight
Why bentley Nevada use negative voltage in proximitor?
Thanks to a bit of research performed by Sir Humphry Davy for the British Navy, we have a technology known as "cathodic protection." First developed to keep the copper hulls of British naval ships from corroding, this technology has been applied to protecting everything from oilrigs to gas pipelines to telephony cabinets. By keeping the cabinet frame at a more positive voltage than ground, corrosion is reduced and the life of the equipment is increased. Who would have guessed?
How do you troubleshoot an "Axial Position / Keyphasor Signal Attenuation or Channel Crosstalk" on a GE Speedtronic Mark VI IS200TVBRH2A Vibration Terminal Board?
The IS200TVBRH2A is a specialized Vibration Terminal Board engineered for GE Speedtronic Mark VI systems to interface proximity probes, seismic velocity transducers, and Keyphasor sensors with the VVIB vibration processing VME card. It provides power to eddy current proximity probes (typically $-24\text{VDC}$) and conditions high-frequency raw AC/DC signal feedback. Channel crosstalk or signal attenuation occurs when the board's high-frequency filtering networks drift, or when probe excitation power rails sag under field wiring load.Diagnostic Routine:Audit Proximity Probe $-24\text{VDC}$ Excitation Power: Measure the DC voltage across the Power (-24V) and Common screw terminals for the affected vibration channel on the IS200TVBRH2A. If the supply voltage sags below $-23.0\text{VDC}$, check the channel's onboard surface-mount current-limiting PTC resistors and Zener clamping diodes. A shorted sensor cable or degraded TVS diode drags down the excitation rail, corrupting proximity gap voltage calculations ($mV/\text{mil}$).Scope Raw Buffer Output Signals (BNC / Test Points): Connect an oscilloscope to the front-panel BNC raw signal outputs or channel test points on the IS200TVBRH2A. Compare the AC ripple ($1\times/2\times$ running speed vibration) and DC bias gap voltage against field proximitor output readings. If the signal is attenuated at the board's cable header output (JR1/JS1), an onboard signal-conditioning operational amplifier or high-pass filter capacitor has suffered thermal breakdown.Verify Shield Terminal Isolation & Common-Mode Noise: Measure resistance between the shield terminals on the terminal block and the panel chassis ground with field wiring disconnected. High common-mode noise or an improper ground loop ($
What causes an "Intermittent Proximity Probe Bias Voltage Drift" on an IS230TVBAH2A Vibration Input Assembly, and how do you isolate a noisy transducer channel?
The IS230TVBAH2A (part of the TVBA/NVBH vibration monitoring family) is an I/O Assembly designed for GE Mark VIe systems to process dynamic vibration, shaft position (Keyphasor), and seismic signals from Bently Nevada proximity probes or accelerometers. Proximity probes require a clean, constant negative DC bias supply (typically $-24\text{VDC}$) to measure gap distance correctly. A "Bias Voltage Drift" causes false vibration spikes, incorrect gap distance readings, or phantom high-vibration trips in the control software. Troubleshooting Strategy: Measure Field Transducer DC Gap Voltage: Disconnect the suspect channel’s signal wire at the terminal block and measure the DC voltage between the Signal and Common terminals using a high-impedance multimeter. For a standard proximity probe, the DC voltage directly correlates to probe gap (typically $-8\text{VDC}$ to $-12\text{VDC}$ for a standard gap). If the DC voltage reads $0\text{V}$ or drifts wildly, check the field proximitor power source. Test Onboard $-24\text{VDC}$ Transducer Power Distribution: The IS230TVBAH2A supplies regulated $-24\text{VDC}$ excitation to each field channel through localized current-limiting circuits. Measure the power rail at the terminal block. If the excitation voltage sags below $-23\text{VDC}$ under load, an onboard ceramic filtering capacitor or current-limiting resistor on that channel path has degraded. Scope High-Frequency Noise on the Signal Path: Connect an oscilloscope to the raw buffered AC output test points. High-frequency electrical noise (induced by adjacent variable frequency drives or poor cable shielding) superimposed on the raw $mV$ vibration signal can saturate the assembly's front-end A/D converter, triggering false bias drift alarms. Unstable vibration monitoring can cause false trip commands or fail to detect severe rotor dynamics issues. Sourcing high-precision vibration hardware requires absolute signal verification. World of Controls provides maximum machinery protection by stocking fully tested IS230TVBAH2A vibration assemblies. WOC subjects every channel to dynamic signal injection sweeps and power rail stability tests to ensure clean, accurate vibration tracking.
