VIBRO-METER VM600 TQ 412 111-412-000-012 Proximity Transducer

Product Overview

The TQ 412 111-412-000-012 (TQ412) is a high-reliability, non-contact proximity transducer designed for high-precision displacement monitoring in extreme industrial environments. Utilizing the eddy current principle, this sensor is a cornerstone of the Vibro-Meter product line for measuring relative vibration and axial shaft position. It is specifically engineered for reverse-mount applications in steam, gas, and hydraulic turbines, as well as high-capacity pumps and turbo-compressors. By providing continuous, accurate data to the VM600 machinery protection system, the TQ412 plays a vital role in predictive maintenance and preventing catastrophic mechanical failure.

Technical Configuration (Deep Dive)

The 111-412-000-012 part number designates a specific hardware build optimized for integration with the IQS 450 signal conditioner.

• Reverse-Mount Architecture: Unlike standard probes, the TQ412 is designed to be mounted through the machine housing or a bracket from the rear, making it ideal for space-constrained internal bearing monitoring.

• Target Interaction: The sensor tip houses an induction coil that generates a high-frequency magnetic field. When positioned near a metallic target (typically a shaft), eddy currents are induced, which the IQS 450 translates into a precise voltage or current signal.

• Material Durability: The transducer tip is made of Torlon (polyamide-imide), while the body is constructed from AISI 316L stainless steel, ensuring resistance to high temperatures and corrosive lubricants.

• Interchangeability: As part of a calibrated measurement chain, each TQ412 component is fully interchangeable with other Vibro-Meter components of the same specification without requiring field recalibration.

Technical Specifications

Technical FAQs

What is the significance of the 111-412-000-012 suffix?

The suffix defines the mechanical configuration, including the reverse-mount body style and the specific integral cable length. For the TQ412, this configuration is optimized for a 4 mm linear range when paired with the correct IQS 450 ordering option.

Can this transducer be used in hazardous environments?

Yes. The TQ 412 is certified for use in potentially explosive atmospheres. It carries Ex ia IIC T6...T3 (Intrinsic Safety) and Ex nA II T6...T3 (Non-sparking) certifications, making it suitable for global oil and gas installations.

Is an extension cable required for this model?

The TQ412 includes an integral coaxial cable. Depending on the distance to the IQS 450 conditioner, an EA 402 extension cable may be required to reach the standard system lengths of 1 m, 5 m, or 10 m.

Engineering & Installation Guide

• Gap Voltage Calibration: For a 4.0 mm range, the sensor should be gapped to achieve a center-point voltage of approximately -10 VDC. This allows for a linear swing of +/- 2 mm of shaft movement. Use a calibrated digital multimeter at the IQS 450 output terminals during installation.

• Mounting Torque: When installing the reverse-mount body into a threaded boss or adapter, do not exceed the specified torque for AISI 316L components. Over-tightening can cause micro-fractures in the Torlon tip or stainless steel housing, leading to pressure seal failure.

• Target Material Note: Standard calibration is performed using VCL 140 steel (1.7225). If the target shaft is made of a significantly different alloy, onsite "Target Material Compensation" must be performed within the VM600 MPS software to maintain E-E-A-T level accuracy.

Engineering Advantages

The TQ412's primary advantage is its Temperature-Compensated Design. While standard eddy current probes suffer from "thermal drift"—where temperature changes are misinterpreted as shaft movement—the TQ412 maintains high linearity across its entire -40 to 180 deg C range. Furthermore, its IP68 protection rating for the transducer head and integral cable ensures long-term stability even when fully submerged in hot turbine oil.