TD GUARD™ Intelligent TD sensor

TD GUARD™|Intelligent TD sensor

Intelligent TD sensor

Ultimate solution for transformer monitoring

TD GuardTM Intelligent Sensor is an on-line CONTINUOUS Capacitance and tan-δ monitoring system for transformer bushings.

The TD GuardTM Intelligent Sensor is providing absolute Tan-δ measurement in on-line permanent monitoring of transformer bushings, granting the best level of diagnostic leverage and reliability.

  • Power Transformer


  • Innovative instrument for Capacitance, Tan-δ and Δtan-δ recording, storage & processing
  • Zero drifts, innovative design for high thermal stability levels without drifts
  • Fast response and accuracy



TD GuardTM Intelligent Sensor consists of a microprocessor-controlled unit supporting sophisticated sensors and conditioning front end. Fiber optic interfaces allow data download by a standard PC or a server able to record values of Δtan-δ (relative measure) and Capacitance and threshold setting.

TD GuardTM has the capability to present two alarm levels, according to a traffic-light approach, using the dedicated LED front lights or activating external alarms media by dry contact interface.
False alarms are avoided through advanced signal processing and field-proven algorithms able to eliminate the effect of noise or other environmental conditions that could lead to wrong diagnosis and inappropriate corrective actions.

TD GuardTM implements transformer bushing’s on-line monitoring through Capacitance and relative Δtan-δ measurement. Smart sensing algorithms are applied to obtain fast response and accuracy.

This intelligent sensor is designed to be used with TECHIMP PD analyzer, as the PDCheck unit and any DGA, providing Global diagnostic coverage and, thus, superior failure prevention. It may also be used as a stand alone device to get basic alarms on programmable threshold levels.