Stafford, Texas

NIVOSWITCH Level Switch for Liquids, Vibrating Fork

NIVOSWITCH Level Switch for Liquids, Vibrating Fork

NIVOSWITCH vibrating fork level switches for liquids are commonly mounted on pipes, silos, tanks, or hopper bins. There, they can be used to control filling and emptying processes and work as fail-safe alarms that provide protection from overfill or dry runs. The plastic coated version is recommended in aggressive mediums and a highly polished version is recommended for abrasive mediums. The PNP/NPN transistor output versions can be connected directly to a PLC or relay unit. There is also a level switch intended for use with solids: NIVOSWITCH for Solids.

  • compact and mini compact type
  • rod extension up to 10 feet
  • switching performance does not depend on the change of liquid conductivity, dielectric constant, pressure, and temperature
  • hygienic versions with various process connections and 0.5 micron fine polishing
  • adjustable sensitivity
  • relay or electronic output
  • medium temperature maximum 266˚F
  • IP67 and IP65/IP68 protection


The NIVOSWITCH is a vibrating fork level switch. It’s ideal for use in shale oil and gas fields. There are currently hundreds of NIVOSWITCH, from NIVELCO, in use in the United States in field production tanks, condensate tanks, separators, and more. This level switch can install vertically or horizontally and can perform as either a high-level switch or a low-level switch. API recommended practice states that unmanned facilities should be instrumented with both a continuous level transmitter, as well as a high level shut off switch to prevent overfill.

  • no moving parts
  • self-cleaning in most mediums
  • stainless steel and plastic-coated probes
  • pipe extension up to 10 feet
  • various output configurations
  • high or low fail-safe mode
  • plastic, aluminum, or stainless steel housing
  • explosion-proof variants available
  • for corrosive, thick, turbulent, and flowing liquids
  • medium pressure: up to 580 psig
  • 3 year warranty
Supply Voltage 20-255 V AC, 20-60 V DC
Ambient Temperature −40 to 158˚F
Process Temperature −40 to 266˚F
Process Pressure maximum 580 psig
Output 1 or 2 relays (SPDT), 2-wire AC / DC, transistor (PNP, NPN)
Process Connection 1″, 1½”, 2″ or flanges or hygienic fittings
Ingress Protection IP67, IP68, IP65
Approvals ATEX, IEC Ex, DNV (Marine), UKCA Ex

NIVOSWITCH Vibrating Fork Level Switch for Shale Oil and Gas Fields

NIVELCO NIVOSWITCH R−400/500 vibrating fork level switches with a parallel vibrating fork are suitable for detecting the level of liquids. Mounting on pipes and tanks, it can control filling and emptying and can also generate fail-safe alarms providing overfill or dry-run protection.

The operating principle is based on that the electronic circuit excites a vibration in the fork probe. When the medium reaches and covers the fork, its vibration changes. The fork will start vibrating freely again as the medium sets it free. Its electronics sense the change of vibration and give an output signal after a selected delay. The plastic-coated version is ideal for use in aggressive media, and the high polish version is ideal for use in abrasive media.

PNP/NPN transistor output versions can connect directly to a PLC or relay unit. Certain types of NIVOSWITCH vibrating forks are able to solve switching tasks of high-current loads with the help of UNICONT PKK switching amplifiers. Additionally, a hazardous area rating NIVELCO UNICONT PKK–312–8 Ex is an intrinsic safety switching unit for Ex-rating vibrating forks.


Hazardous Area Rating Level Switch

  • ATEX: Ex ia G, Ex d G
  • IEC: Ex (Ex d G)
  • UKCA: Ex (Ex ia G)
  • DNV: only for RF–400 compact types for liquids

Common Uses of Level Switches

  • chemical industry
  • food and beverage
  • power plants
  • oil industry
  • water industry
  • most liquids with minimum 0.7 kg/dm3 density (specific gravity) and maximum 104 mm2/s (0.1 ft2/s) viscosity
  • for liquids / free-flowing, powdered solids, and granules
  • for normal or hazardous, aggressive (acids, solvents) liquids or high viscosity liquids
  • covers a large variety of level detection applications such as high/low fail-safe limit switch or dry run protection, pump controls

NIVOSWITCH Series Vibrating Fork Level Switch Model Line-Up

Type selection is aided by this table for choosing the proper version to a given level switching task. Most essential aspect is the consistency of the measurement medium.

For Liquids For Solids
Features Mini Compact Compact Mini Compact Compact
Metal Housing X X X X
Plastic Housing X X
Extension X X X X
Highly Polished Version X X
Plastic Coated Fork X X
1″, 1 1⁄2″ Process Connection X X X X
2″ Process Connection X X
Relay Output X X
Electronic Output X X
Electrical Connection Terminal X X
DIN Connector X X
M12 Connector X
Cable X X
Intrinsically Safe Version
(Ex ia)
Flameproof Enclosure
(Ex d)
Dust / Explosion Proof Version
(Ex ta/tb IIIC)
Fail-safe Setting
(low-high level)
X* X X* X
Function Indication X X X X
Density Selection X X
Output Test Magnet X X

*Only for 3-wire DC versions