Description
SCHENCK VLB20120
Technical Specifications: Model: VLB20120 Measurement quantity: Vibration velocity Measurement range: 0~20 mm/s RMS Output signal: 4-20mA two wire loop powered Power supply: 12~30VDC loop power Frequency response: 10Hz ~ 1000Hz Mounting: Surface mounting on machine casing Operating temperature: -20℃ to +80℃ Protection class: IP67 Housing material: Stainless steel
Functional Features: Integrated velocity sensor and transmitter in single compact housing. Two wire 4-20mA output proportional to casing vibration RMS velocity. Wide frequency response range for general industrial machinery vibration. Robust stainless steel housing suitable for field mounting. IP67 enclosure for dust and moisture protection. Built-in over range protection for high vibration impact. Simple installation without separate signal conditioner module.
Application Scenarios: Industrial fan casing vibration monitoring, centrifugal pump vibration supervision, electric motor condition monitoring, small compressor casing vibration measurement, conveyor auxiliary machinery vibration monitoring, HVAC large fan predictive maintenance.
Performance Parameters: High measurement stability in wide temperature range. Good vibration shock resistance for field machine environment. Linear 4-20mA output within full measuring range. Low power consumption from two wire loop supply.
Material Composition: Stainless steel metal housing. Piezoelectric velocity sensing element. FR4 printed circuit board with signal conditioning circuit. Hermetic sealing rubber gasket. Stainless steel mounting base and threaded connector.
Structural Features: Compact cylindrical stainless steel housing. Bottom threaded hole for mounting stud installation on machine casing. Top side cable gland for signal cable entry. Hermetically sealed internal cavity to prevent dust and moisture ingress. Internal sensing element fixed with shock absorbing structure.
Working Principle: Piezoelectric sensing element inside transmitter captures casing vibration velocity. Vibration movement generates charge signal from piezoelectric element. Internal signal conditioning circuit converts charge signal to RMS velocity value and outputs standard 4-20mA two wire signal. The 4mA output corresponds to zero vibration and 20mA corresponds to full scale 20mm/s vibration velocity. The transmitter receives power from the same 4-20mA signal loop without separate power cable.
Installation Requirements: Mount transmitter on rigid flat surface of machine casing using mounting stud. Install at position with strongest casing vibration transfer. Use shielded two wire cable for 4-20mA signal wiring. Tighten cable gland to maintain IP67 protection. Route cable to avoid mechanical pulling and abrasion.
Usage Notes: Avoid mounting on thin flexible casing plate which causes measurement error. Check cable insulation integrity periodically. Do not apply mechanical impact on transmitter housing during installation. Verify loop power supply voltage meets requirement. Inspect mounting stud tightness regularly for vibration environment.
