Nivelco has a line of the products that are FM approved. We wanted to show you which of the product line are FM approved.
PiloTREK Pulse Burst Radar Level Transmitters
The 25 GHz (K-band) PiloTREK Pulse Radars are regarded as the most progressive non-contact level transmitters of the industrial process automation field. Their accuracies are excellent and their short and narrow antennas make their installation simple and low cost. NIVELCO’s K-band radar featuring ±3 mm (0.12 inch) accuracy and short dead band excels with its versatile housing concept lining up plastic, aluminium and stainless steel versions. Its antenna range incorporates stainless steel horn or parabolic planar antenna and enclosed plastic tube varieties. The enclosed antenna versions can be replaced without removing the antenna enclosure from the process. Local programming of the PiloTREK is aided by a plug-in display module. If on-site reading is not desired this module may not be required thus reducing cost of ownership. The signal processing algorithm of the PiloTREK is based on NIVELCO’s 35 years of experience with non-contact level measurement making it an excellent choice for applications simple and challenging alike.
OPERATION
The operation of the non-contact microwave level transmitters is based on the measurement of the time of flight of the microwave burst. The propagation speed of microwave impulses is practically the same in air, gases and in vacuum, independently from the process temperature and pressure, so the measured distance is not affected by the physical parameters of medium to be measured. The level transmitter induces microwave impulses a few nanosecond long in the antenna and a part of the energy of the emitted signals is bounced (reflected) back from the measurement surface depending on the measured media. The time of flight of the reflected signal is measured and processed by the electronics, and then this is converted to distance, level or volume proportional data. The measurability of the level of a specific medium is depending on the signal strength of the reflected microwave impulses. The signal strength of the reflected impulses is considerably depending on the distance to be measured, the relative dielectric constant of the measured medium and the turbulence of the surface. The relative dielectric constant (εr) of the medium should be more than 1.4 in case of parabolic design, or it should be more than 1.9 with horn antenna types.
NIVOTRACK MAGNETOSTRICTIVE LEVEL TRANSMITTERS
NIVOTRACK magnetostrictive transmitters are an ideal solution for high accuracy measurement of clean fluids. Its high precision renders the NIVOTRACK suitable for custody transfer measurement of liquids such as fuels, solvents, alcohol derivatives etc. Units with flexible tube do not only make this accurate measurement for higher tanks possible, but offer a more convenient way for shipment and installation. Plastic coated versions of the NIVOTRACK substantially expand the field of application by a wide range of aggressive materials. Integrating the transmitter into a process control system is easy thanks to the intelligent signal processing and communication software as well as the wide of range of accessories offered.
OPERATION
A float containing a magnetic disc moves along a guide tube with the specific magnetostrictive wire in it. A pulse generated by the electronics travels along the
magnetostrictive wire. At the point the pulse reaches the float’s magnetic field, a torsion develops. Reflected from the torsion point, the pulse creates an acoustic wave that travels back along the wire. The 4-20 mA output of the transmitter is proportional to the elapsed time between the excitation and detection.
NIVOSWITCH VIBRATING LEVEL FORK SWITCHES
are suitable for level detection of liquids or granular, powdered solids. Units with parallel vibrating fork are suitable for liquids, units with non-parallel vibrating fork are suitable for solids. Mounted on pipes, silos, tanks or hopper bins filling / emptying can be controlled using these devices just as well they can generate fail-safe alarms providing overfill- or dry run protection. The operation principle is based on the electronic circuit exciting the fork probe making it vibrate. As the medium reaches and covers the fork its vibration changes, or stops. The fork will start vibrating again as the medium sets it free. The electronics senses the change of vibration and gives output signal after a selected delay. Plastic coated version is recommended in aggressive mediums, highly polished version is recommended for abrasive mediums. The PNP / NPN transistor output versions can be connected directly to PLC, or relay unit. The NIVOSWITCH vibrating forks are able to solve switching tasks of highcurrent loads with the help of UNICONT PKK switching amplifiers. The UNICONT PKK-312-8 Ex intrinsically safe switching unit is designed to serve Ex rated vibrating forks.
