Introduction

Monitor your solid or liquid level with our wide range of level transmitter and switches from Flowline, Kari-Finn and Kansai Automation. Suitable for harsh environment, ATEX and corrosive condition.

liquid level measurement flowline map (1)
solid level measurement flowline map

Sciengate offer's a level sensors from Flowline,Kari-Finn and Kansai Automation to detect the level of liquids and other fluids and fluidized solids, including slurries, granular materials, and powders that exhibit an upper free surface. Substances that flow become essentially horizontal in their containers (or other physical boundaries) because of gravity whereas most bulk solids pile at an angle of repose to a peak. The substance to be measured can be inside a container or can be in its natural form (e.g., a river or a lake). The level measurement can be either continuous or point values. Continuous level sensors measure level within a specified range and determine the exact amount of substance in a certain place, while point-level sensors only indicate whether the substance is above or below the sensing point. Generally the latter detect levels that are excessively high or low.

How to choose the correct level sensor?

What material will the sensor contact?

A sensor must be compatible with the fluids or materials to which it will be exposed. If the sensor will contact any caustic, corrosive or aggressive materials, it must be able to withstand them while maintaining proper functionality. For example, a metal sensor used to measure critical process fluids could release metal ions or particles and contaminate the fluid. In this situation, selecting a sensor made out of a fully compatible material is best.

Are solids or liquids being measured?

his is an extremely important question that must be considered upfront. Float-type sensors normally are a good solution for measuring liquids. However, when measuring solids, float-type sensors are impractical.

The following is a list of popular sensor types and the materials with which they are compatible:

  • mechanical float sensors —fluids only;
  • electromechanical (tuning fork or staff-based) —solid substances only;
  • ultrasonic — both solids and fluids; and
  • radar — both solids and fluids.

Remember, other design conditions besides the type of substance being measured could cause one of these sensors to perform better than another. The material being measured is just one factor to consider in device selection.

Where and how will the level sensor be placed — internally or externally?

This question is important from a logistical standpoint. External sensors could require additional plumbing and installation costs while internal sensors may throw off production amounts or limit tank capacity. Some systems incorporate an internal sensor and an external display to convey information. In this case, always consider the requirements of both the internal and external components.

What temperatures and pressures will the sensor face?

When considering temperature, sensors generally fall into two categories: those built to withstand extreme heat or cold, and those limited to common room temperatures. For example, a metal sensor will withstand an extremely hot environment much better than a polytetrafluoroethylene one. As far as pressure, most sensors can handle 0 to 100 psi — but an extremely high pressure environment or vacuum could cause rupture or malfunction.

What is the density of the material?

This question applies almost exclusively to fluids. Those that are fairly dense or contain floating solid particles often require more-complicated level measurement sensors. So, for example, a simple float sensor will suffice in a water cooler tank but may experience difficulties measuring rough crude oil because of the viscous nature of that fluid. A material also may include a mix of fluids such as oil and water. In such a case, a capacitance sensor can accurately measure the mixture. A magnetic float sensor with the buoyancy factor adjusted to the material would work, too.

What is the size and shape of the tank?

A vessel’s dimensions and form directly determine the placement of the sensor in relation to the material. This is because different materials fill containers in different ways. Liquids occupy the lowest areas first and rise with a level surface while powders and other solids often stack to a point and leave lower areas empty — perhaps requiring placing the sensor directly in the middle so it can accurately measure the highest point of the material.