Installation Position and Switching Point of Vibrating Rod Level Switch

Vibrating Rod Level Switch is based on a cantilever beam vibrating principle. A cylindrical rod or a fork is used as a vibrating probe. Piezoelectric devices are utilized to drive and detect the vibration. With state-of-the-art techniques, the specifications of our vibrating level switch and its reliability reach to an advanced level in the field. When vibrating probe comes in contact with measured material, vibrating amplitude and frequency of the probe will substantially decrease, so does the output of detecting piezoelectric device. The amount of decrease is analyzed by an intelligent circuit which outputs a switching signal as a result.

Generally, Vibrating Rod Level Switches are mounted with thread or flange connections. The two most commonly installation positions are vertical and horizontal installation.

1. For vertical installation, install level switch at a distance of d/6 from the vessel’s wall.

2. For horizontal installation, mount approx.20°inclined to the horizon to avoid medium buildup. To protect the probe from direct impact damage, a protection baffle should be installed above the vibrating body, and longer than intrusion depth (horizontal). Generally, protection baffle can be a convex shape (inverted “V” section). If medium is coarse and abrasive, baffle in concave shape (erected “v” section), so medium could stack up a bit in concave area. For non food materials with large particles and high density, when the probe may be impacted by vertical falling, niche installation can also be adopted to better measure and prolong the service life of the instrument.

In addition, Vibrating Rod Level Switches can also be mounted from the bottom with upward probe at limited space, and the round rod level switch is recommended for accurate and reliable measurements.

Depending on different applications, selecting appropriate installation positions is related to the switching points. Generally, the effective length of the vibrating probe is 125mm. For vertical installation, it alarms when material is accumulated to about 30mm from the probe’s end; for lateral installation, such as horizontal installation, usually the alarm sirens when material accumulates to half of the probe. If install laterally with an angle, its switching point is similar to that on the top; if install from the bottom with upward probe, the materials are generally piled up from probe’s root, but the most sensitive part is at the 1 / 3 length from its end part. In fact, the switching point will also be different based on the material density and specific gravity. Therefore, it is possible that the alarm outputs when material is piled up to half of the probe or to the probe’s end for different application properties.