General
What is a Level Indicator?
Level indicator is a broad term frequently used to describe any device that measures the level of either a liquid or dry material. Level Indicators are available in various technologies, including point level switches, continuous level measurement sensors and visual site instruments, commonly referred to as Magnetic Level Indicators. Choosing the best level indicator will depend upon the application, process conditions and the user’s desired outcome.
What is a Level Switch?
A Level Switch is a sensor that detects the presence of liquids, powders and other dry materials at specific locations inside of tanks, vessels, bins, hoppers or other containers. Level switches are commonly installed at the top of tanks as a high level alarm in order to prevent overflows. As the material rises and contacts the switch, an output signal is sent to a light, horn, PLC or other type of controller to prevent an overflow. In other cases, a level switch can be installed towards the bottom of a tank as a low level alarm to signal when the level has dropped below a certain point, preventing the vessel from completely draining. Level switches can be used as primary level indication or in conjunction with transmitters as secondary, backup instrumentation to provide redundancy.
What is a Level Transmitter?
A Level Transmitter is a sensor that provides continuous level measurement over an entire range rather than at a single point. Level Transmitters provide an output signal (4/20mA) that directly correlates to the level inside the tank or vessel. The output signal can be run to a local display or sent back to a PLC or other type of controller. In either case, the level transmitter indicates where the level is at all times, similar to the gas gauge in a car. Level transmitters can be used as either primary level indication or in conjunction with other types of level sensors such as level switches and/or magnetic level indicators.
What is an Oil/Water Interface detector?
Oil Water Interface detectors are instruments that sense the interface level between oil and water. The higher density water sinks to the bottom while the lighter, less dense oil floats to the top. The point or level at which these two meet is referred to as the interface. The oil/water interface detector senses the interface level and sends a signal back to an alarm, PLC or other type of controller. These instruments are commonly used in SKIDS, pipes, separators and drainage systems.
What is an Ultrasonic Level Transmitter?
Ultrasonic Level Transmitters are a non-contact level sensor that operate on the Time-of-Flight principle. The sensor generates a pulse that sends a sound wave from the transducer face down to the fluid level. The media reflects the signal and the transit time is converted into a 4/20mA output signal. Ultrasonic level sensors provide simple and reliable continuous measurement of fluids that do not contain foam, vapors, fumes or gases and are suitable for use in either plastic or metal tanks, sumps, containers or other vessels.
What is a Radar Level Transmitter?
Radar Level Transmitters are a type of non-contact level sensor that operate on the Time-of-Flight principle. The sensors electronics transmit an electromagnetic pulse that travels down to the fluid surface. The media reflects the signal back and the time of flight is measured and converted into a 4/20mA output signal. Non-contact Radar level sensors provide reliable, maintenance free continuous measurement of liquids inside metal tanks or vessels. Radar level sensors are designed to operate in environments with more extreme process conditions, such as in a vacuum, high pressure, high temperature, foam, vapor or other gases – conditions that would normally interfere with ultrasonic type sensors. Radars level sensors are perfect to use with corrosive liquids, thick fluids, slurries or other applications where direct contact with the media would not be desired.
What is a Magnetic Level Indicator?
Magnetic Level Indicators, also referred to as Magnetic Level Gauges, are a type of level sensor that provides visual level measurement. Magnetic Level Indicators consist of a chamber, a magnetic float and a flipper type indicator scale mounted to the side of the chamber. The float inside the chamber rises and falls with the fluid level inside the tank, changing the orientation of the flippers and providing a visual level indication that can be seen up to 100 feet away. Magnetic level gauges are an excellent alternative to sight glasses and provide a non-invasive, low maintenance, cost effective level solution. They are especially safe for flammable, toxic, corrosive liquids because the fluid never contacts the glass – should the glass break, there is no possibility of leakage.
Are Babbitt Level switches an appropriate crossover for part numbers L2000, L3520, L3521, L3522, L3540 or L3541?
Absolutely, Babbitt Level switches are very similar with only slight differences in specifications. In order to determine which Babbitt Point Level Switch is right for your application, we will need more information about your particular application. Please contact us via the contact us or request a quote submission form.
Are Babbitt continuous level transmitters an appropriate crossover for part numbers L2610, L2631, L3610 or L4610?
In most cases, yes, however there are variances in products and specifications. In order to determine which Babbitt continuous level transmitter is a suitable replacement we will need to gather more information about your application. Please contact us via the contact us or request a quote submission form.
Level Switch
Are Babbitt Level switches an appropriate crossover for vibrating tuning forks?
Absolutely. Vibrating tuning fork switches have a fork shape sensing element which vibrates. As material comes into contact with the forks this vibration begins to dampen. The dampening of the signal is sensed by the circuitry and gives the desired output. Babbitt Level switches use a radio frequency signal which sends a sign wave down the probe. Any material that comes into contact with the probe decreases the amplitude of the signal. The circuity senses the change insignal and gives the desired output. While the technology between the two are different, the end result is the same – product is sensed and an output is given. However, unlike vibrating tuning forks, Babbitt Radio Frequency Level switches are not as susceptible to product buildup making them better suited for applications where buildup is a concern.
Are Babbitt Level switches an appropriate crossover for rotating paddle switches?
Absolutely. Rotating paddle switches have a paddle which rotates. As material comes into contact with the rotating paddle, the rotation slows, product is sensed and the circuitry gives the desired output. Babbitt Level switches use a Radio Frequency signal which sends a sign wave down the probe. Any material that comes into contact with the probe decreases the amplitude of the signal. The circuity senses the change in signal and gives the desired output. While the technology between the two are different, the end result is the same – presence or absence of material is sensed and an output is given. However, unlike rotating paddle switches, Babbitt Level switches have no moving parts. There are no motors to burn up, paddles to fall off or bearings to wear out. In addition, Babbitt Level switches are not as susceptible to product buildup which makes them better suited for dry bulk solid applications.
What is the highest temperature Babbitt Level switches are designed to handle?
Standard Babbitt Level Switches are capable of handling temperatures ranging from 180F to 450F depending upon the model and insulator material. Teflon insulators can be added to increase temperatures up to 450F. High temperature level sensors are available by adding a PEEK insulator to any level switch model, allowing for temperatures up to 550F in both liquid and dry materials. For high temperatures applications above 550F, a custom LS8000 high temperature level sensor with ceramic insulator can be utilized in dry materials to allow for operations in temperatures up to 1200 F.
How are your probe lengths measured?
Probes are measured from the end of the process connection to the tip of the probe.
How long and short do you make your probes?
Rigid probes are available in lengths up to 12 feet and cable probes in lengths up to 100 feet. In most application, probes as short as 4 inch can be used. In very specific applications, probes as short as 1” are available.
Can I cut a probe if it’s too long?
A bare stainless steel probe can be cut with a hacksaw, however it is recommended to leave at least 2-3” of exposed stainless steel probe past the insulator. If the probe has a coating, the probe cannot be cut as doing so would compromise the coating.
I ordered a probe that is too short, what can I do?
If the probe is bare stainless steel, it can be welded onto to desired length. If the probe has a coating, the unit will need to be sent back and re-worked for the desired length.
Can a Babbitt Level Switch be used to ignore FOAM?
Yes, but it will depend upon the application. If the media is conductive (water based), a coated probe such as HALAR or TEFLON will need to be used. If the media is non-conductive, a bare stainless steel probe can be utilized. In either case, the level switch is calibrated to ignore the foam and yet still sense the level.
What is HALAR?
HALAR is a fluoropolymer coating with similar chemical resistance characteristics to Teflon.
What’s the difference between HALAR and Teflon?
HALAR’s chemical characteristics allow for a thicker coating to be applied to the probe. HALAR also tends to be less expensive than Teflon. Teflon, on the other hand, has superior release properties and may be better suited in certain food applications.
Dual Point RF Switches (LS7000/2 LS8000/2)
How short can the measuring range be on a dual point RF switch?
6 inches.
Would a LS7000/2 or LS8000/2 work well in dry material applications?
No, we do not recommend LS7000/2 or LS8000/2 units in dry material applications due to the low conductivity and varying bulk density. Two separate point level switches would be a better solution.
What liquids are suitable for the LS7000/2 and LS8000/2 dual point switches?
The radio frequency dual point level switches are designed to work in homogeneous liquids, such as water, acids and solvents. Liquids that change in conductivity or applications where various materials may be in the vessel at different times are undesirable applications. If this is the case, please use two probes.
Can I use a dual point switch in an application that will possibly leave a buildup on the probe?
No. Material sticking on the probe will affect set point repeatability. If this will be a problem, we strongly recommend using 2 separate single point level switches instead of the LS7000/2 or LS8000/2 switches.
LT 9000
Will the LT9000 work in a NON-conductive application?
No, when we boost the LT9000 signal enough to work in non-conductive applications it becomes unstable so we suggest limiting it to conductive media.
Does the probe on an LT9000 need to be coated?
Yes, because the LT9000 is limited to electrically conductive applications a coating is required in order to electrically isolate the probe from ground.
LTM Transmitters
What is the difference between the LT-1 transmitter and the LTM 250/350 transmitters?
The LT-1 is an analog transmitter (4/20 mA output) with no digital display. The LT-1 provides step up level in ½” increments through a series of reed micro switches. LT-1 transmitters offer a low cost continuous level measurement solution and are ideal for applications that have vibration and/or when precise accuracy is not desired (1/2”). The LTM 250 & LTM 350 are both Magnetostrictive transmitters, which are both highly accurate and therefore better suited for users seeking precise level indication. LTM transmitters provide a 4/20mA output and have options for various communication protocols such as HART or Field Bus (LTM350) as well as dual float configurations for interface applications. Both the LT-1 and LTM transmitters come standard with CSA/US Explosion Proof Approvals.