As the core equipment for rotating machinery condition monitoring, vibration velocity sensors are widely used in industrial fields such as steam turbines, pumps, and fans. In actual engineering applications, the installation direction of the sensor directly affects its measurement accuracy and reliability. Taking the VS-2X vibration velocity sensor as an example, its design supports vertical, horizontal, or vertical-horizontal dual-purpose installation, but whether the sensitivity difference in different directions needs to be compensated on site has become the focus of users.

1. The correlation between the working principle of the vibration sensor and the installation direction

The VS-2X vibration sensor works based on the principle of electromagnetic induction. It generates induced electromotive force by cutting the magnetic lines of force through the moving coil, and converts mechanical vibration into a voltage signal proportional to the speed. Its core structure consists of a fixed coil, a magnetic steel, and an elastic element. The sensor is fixed on the surface of the device under test through a base to directly sense the vibration of the device. Since the output signal of the sensor is proportional to the vibration velocity, the accuracy of its measurement results is highly dependent on the installation position and direction.

In equipment such as steam turbines and pumps, the vibration direction is usually complex. For example, the shaft vibration of a steam turbine may contain radial and axial components, while the vibration of a pump may be affected by both fluid dynamics and mechanical structure. The sensor installation direction needs to be consistent with the main vibration direction to ensure that key vibration characteristics are effectively captured. However, when the sensor is installed in different directions, whether its sensitivity changes due to mechanical structure or environmental factors is the key to determine whether field compensation is required.

2. Impact of installation direction on vibration sensor performance

The VS-2X vibration detection sensor is designed to allow installation in vertical or horizontal directions, and has a sensitivity range of 20~50 mV/mm/s. From the technical parameters, its frequency response range is wide, and its natural frequency is about 10 Hz, which is suitable for vibration monitoring needs of most rotating machinery. However, the difference in sensor sensitivity may come from the following two aspects:

Gravity effect of mechanical structure

When installed vertically, the internal magnets and elastic elements of the vibration probe may be affected by gravity, resulting in changes in initial displacement or stress distribution. This slight mechanical offset may affect the sensor’s response characteristics to low-frequency vibration, especially in the vibration range close to its natural frequency. In contrast, when installed horizontally, the gravity direction is perpendicular to the vibration detection axis of the sensor VS-2X, which may reduce the impact of mechanical offset and maintain a more stable sensitivity.

Differences in environmental factors

In actual working conditions, the installation direction of the vibration velocity sensor VS-2X may affect its heat exchange efficiency with the surrounding environment. For example, when installed vertically, the heat dissipation path of the sensor may be smoother, while when installed horizontally, the local temperature gradient may be aggravated due to restricted air flow. Temperature changes may cause thermal expansion of the sensor material or drift of electronic components, which in turn have an indirect effect on the output signal. In addition, when installed horizontally, the sensor may be more susceptible to interference from external shocks or mechanical stress, especially during the startup or shutdown phase of the equipment.

3. Necessity analysis of field compensation

Field compensation usually refers to the elimination of system errors through calibration or software correction after the sensor is installed to improve measurement accuracy. For the VS-2X vibration sensor, whether field compensation is required needs to be comprehensively judged in combination with the following conditions:

Accuracy requirements of application scenarios

In scenarios with high requirements for vibration monitoring accuracy, such as bearing condition assessment of steam turbines or mechanical fault diagnosis of pumps, small sensitivity differences may affect the data analysis results. At this time, the output consistency of the vibration motion sensor VS-2X in different directions can be verified through field calibration, and corrections can be made if necessary.

Complexity of the installation environment

If there are significant temperature fluctuations, electromagnetic interference or mechanical vibration superposition in the equipment operating environment, the installation direction may aggravate the nonlinear error of the sensor. For example, in high-temperature areas, vertical installation may cause deformation of the sensor housing due to heat radiation, which in turn affects the relative position of the coil and the magnet. In such cases, it is recommended to reduce the impact of environmental interference through on-site compensation measures.

Long-term stability of the sensor

During long-term operation, the vibration sensor VS-2X may experience sensitivity drift due to material fatigue or reduced sealing performance. If systematic deviations are found in the output of vertically and horizontally installed sensors during regular maintenance of the equipment, targeted compensation adjustments can be made. For example, by comparing the data of sensors installed in different directions on the same equipment, the source of the difference can be identified and corrected.

For equipment such as steam turbines, the shaft system vibration is usually mainly radial, and it is recommended to choose vertical installation to capture the radial vibration component more directly; for pump equipment, the axial vibration may be more significant, and horizontal installation may be more in line with actual needs. The sensor should be installed in a location that can reflect the overall vibration state of the equipment, such as the rigid area of ​​the bearing cover or housing. Avoid installation in loose or easily deformed areas to reduce the impact of installation errors on measurement results. If the equipment requires frequent replacement or adjustment of sensors, choosing a vertical-horizontal dual-purpose sensor can reduce the number of spare parts and reduce the risk of sensitivity differences caused by directional adjustment.

When looking for high-quality, reliable vibration sensors, YOYIK is undoubtedly a choice worth considering. The company specializes in providing a variety of power equipment including steam turbine accessories, and has won wide acclaim for its high-quality products and services. For more information or inquiries, please contact the customer service below:
E-mail: sales@yoyik.com
Tel: +86-838-2226655
Whatsapp: +86-13618105229
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