TQ912-011 111-912-000-011 A5-B1-E1000-F0-G0-H10

Product Overview

Meggitt TQ912-011 (TQ912-011 111-912-000-011 A5-B1-E1000-F0-G0-H10) is a non-contact eddy current displacement sensor, mainly used for measuring shaft vibration, shaft displacement (expansion difference) and rotational speed of rotating machinery. It belongs to the TQ900 series and is designed to replace the older TQ400 series, such as TQ412, offering superior temperature stability and interchangeability. TQ912 and TQ902 are essentially the same, but TQ912 is specifically designed for "reverse installation", that is, the sensor head is facing down or in a direction that is not conducive to wiring, while TQ902 is for standard installation. As the front-end sensing element of the machinery protection system or condition monitoring system.

Product functional features

Temperature compensation design: Built-in temperature compensation circuit ensures stable measurement accuracy within a wide temperature range of -40℃ to +180℃, reducing measurement drift caused by thermal expansion and contraction.

High-reliability connection: Self-locking miniature coaxial connector is adopted to prevent loosening in vibration environments.

Intrinsic safety and explosion-proof: Ex certified versions are provided. If the model suffix contains A5, it is suitable for explosive hazardous areas (gas Zone 0/1/2, dust Zone 20/21/22).

Integrated Diagnosis: When used in conjunction with the IQS900 transmitter, it supports the built-in self-check (BIST) function, which can remotely indicate faults of the sensor, cable or the transmitter itself.

Long-distance transmission: With the IQS900 and GSI127 isolators, the signal transmission distance can reach up to 1km.

Problems encountered during use

A slight abnormal noise occurred during the operation of the centrifugal compressor in a certain petrochemical plant. Maintenance engineers use the TQ912-011 sensor (installed in reverse at the top of the bearing housing) to monitor the radial vibration of the rotor in real time. One day, the system received a significant fluctuation in the AC dynamic signal transmitted by the sensor through the IQS900 transmitter, while the DC static voltage showed an abnormal gap. The system immediately triggered an alarm and shut down. Upon inspection, it was found that the wear of the bearing tiles caused the shaft center to shift. Thanks to the timely early warning of TQ912, severe friction between the rotor and stator was avoided, saving the enterprise from equipment losses amounting to millions of yuan.

Problems encountered during use:

Installation gap issue: If the shaft center is not aligned during installation, it may lead to measurement nonlinearity.

Temperature influence: Although there is compensation, cold and hot state calibration is still required under extreme temperature gradient changes.

Electromagnetic interference: In a strong electromagnetic field environment, a well-shielded extension cable EA902 should be used and ensured to be grounded.

Cable protection: The coaxial cable of TQ912 is relatively thin. In a high-temperature oil mist environment, it is recommended to install a stainless steel flexible hose FEP for protection.