Liquid level sensing is an important aspect of fluid measurement in a range of industries and applications. Sensor Tips helps you stay current on the latest news and information in liquid level sensing by compiling articles and information from a diverse group of sources. Stay up to date on the latest trends by subscribing to our RSS feed today!
Sensing Complements GM’s Fix for Volt Battery Problem
January 6, 2012 by Randy Frank
Filed under Featured, Liquid Level
The innovative Chevrolet Volt suffered a setback when some battery packs caught fire days or weeks after government safety tests. The company has found that National Highway Traffic Safety Administration (NHTSA) crash tests caused a puncture in the side of the battery pack allowing coolant leakage into the pack. Later, the coolant’s interaction with electronics inside the pack ignited the battery cells.
In addition to strengthening an existing portion of the vehicle’s safety structure to further protect the battery pack in a severe side collision and adding a tamper-resistant bracket to the top of the battery coolant reservoir to help prevent potential coolant overfill, a sensor is also part of the solution. The added sensor in the reservoir of the battery coolant system monitors coolant levels to warn the owner if a problem develops.
Capacitive Sensor for Liquid Level Detection
September 15, 2011 by Randy Frank
Filed under Capacitive, Featured, Liquid Level
Detecting liquid levels in confined spaces in machines and facilities can pose problems. For these types of applications, Baumer developed its CFDK 25 capacitive sensor. The 52.4 x 25-mm flat housing design has a height of only 6 mm and has an available mounting frame. In addition to attachment with two screws, the frame allows installation with cable ties, a Velcro fastener or glue.
The capacitive sensor has four fixed nominal sensing distances from 2 to 15 mm offered in a chemical resistance housing made of Polyamid 12 plastic.
For further information on Baumer’s CFDK 25 capacitive sensor, click here.
Gems Introduces a New Rugged Metal Electro-Opto Sensor
August 16, 2011 by admin
Filed under Level, Liquid Level
Gems® Sensors & Controls™ (Gems) introduces the new low cost, miniature ELS-950M Series of Electro Optic Level Sensors (ELS) for a wide range of applications and industries.
The ELS-950M Series expands on the existing ELS-950 product line with a brass housing to perform in harsh environments, maintain integrity in temperatures ranging from -40°F to +230°F and pressures to 250 psi.
ELS-950M liquid level sensors feature an over-molded electronics insert, TPE insulated wires, and a flurocarbon O-ring seal to create a watertight, environmentally resistant assembly. The ELS-950M is UL and CE approved to EMI standards and shock and vibration tested to MIL standards, IP66/67 and RoHS compliant. These robust sensors are available in 5 or 12 Vdc models with mounting options of ¼” NPT, ½”–20UNF-2B or M12x1-8.
“With the development of the ELS-950M Series, Gems has continued to expand the broad offering of our ELS product line,” says Kevin Castonguay, Product Marketing Manager for Gems Sensors & Controls. “The product delivers a robust and reliable solution for OEM customers. The small, solid state-sensor is durable enough to handle almost any application or temperature.”
The compact size, durability, and low cost of the sensor creates an excellent option for liquid level applications in medical diagnostic equipment, sterilizers, washers, dialysis equipment; lubricant systems in machine tools, generator sets, on- or off-road vehicles; hydraulic fluid reservoirs; HVAC and refrigeration systems; radiators and fluid overflow containers and OEM food and beverage applications.
Gems Sensors & Controls
www.GemsSensors.com
Gems Introduces New Line of High Precision Magnetostrictive Level Sensors
June 9, 2011 by admin
Filed under Level, Liquid Level
Gems® Sensors & Controls™ (Gems) announced the launch of the new XT-1000 series of magnetostrictive continuous level sensors for OEM and end user applications.
The XT-1000 series offers a line of robust, stainless steel sensors with highly accurate continuous level measurement in lengths from 8 inches to over 13 feet. The XT-1000 measures liquid media levels using the complete probe length and is largely unaffected by temperature. The sensor offers constant sensing of fluid level regardless of the physical state of the media including: bubbles, foam, condensation, precipitation, pressure, temperature or changes in density.
The use of magnetostriction is ideal in applications that require extremely accurate indication such as the chemical and water treatment industries. The 4-20mA sensor is compatible with a variety of tank dimensions and offers an explosion-proof version for installation in potentially explosive atmospheres where electrical equipment of category 1 (zone 0) or category ½ (zone 0/1) are required. Also available with the digital Hart protocol operating system, the sensor is able to output the position of the first, second or both floats.
“The XT-1000 increases the breadth of the Gems continuous level product line with a highly accurate magnetostrictive technology solution” says Kevin Castonguay, Product Marketing Manager for Gems Sensors & Controls. “The high resolution sensor is a robust solution for a wide variety of OEM and end user applications such as; chemicals and petrochemicals, biotech and pharmaceuticals, mechanical engineering, water treatment, beverage, food processing and underground storage tanks for leak detection.”
Gems Sensors & Controls
www.GemsSensors.com
Liquid Level Sensor for Food and Beverage Measurements
March 31, 2011 by Randy Frank
Filed under Capacitive, Featured, Liquid Level
Stuff that sticks to the sides of the container makes accurate level measurements difficult. The LMT Series from ifm efector specifically addresses this problem for viscous media and powders in food and beverage processing tanks and pipes.
High frequency (MHz) capacitive spectrum profiling technology enables the sensor to ignore foam and deposit build-up and differentiate between residue and actual product in a tank.
The solution involves sweeping the frequency band of 50 to 200 MHz for the capacitive sensor and taking three measuring points: electromagnetic field damping, permittivity phase shift of the molecule polarization in the magnetic field, and the media conductivity in the electric field. An algorithm in the sensor processes these measurements to calculate the signal amplitude.
For more information including a video about ifm efector’s LMT Series Sanitary Point-Level Sensor, click here.
NASA Develops More Accurate Fuel Tank Sensor
May 6, 2010 by admin
Filed under Level, Liquid Level
NASA has developed wireless sensor technology is giving recreational boat owners safer and more accurate readings of how much fuel is in their tanks.
The NASA-developed magnetic measuring system also has potential use in planes, trains and automobiles.
Originally developed by NASA to retrofit aging aircraft with safety equipment, the technology is a spinoff for designing and using sensors without the shortcomings of many commonly-used liquid storage measurement systems.
Traditional marine fuel-gauge float systems can provide inaccurate readings because of a boat’s movement. A vessel’s pitch and roll in open waters can create a “seesaw” effect on fuel gauges. This new wireless fluid-level measurement system has two stationary pieces of conducting material located in the fuel, connected to an inductor on the outside of the tank.
Another aspect of the wireless fuel-level sensor system is the design can be modified to detect water, a concern for recreational boaters. It also can be modified to detect other non-fuel liquid contaminants in a tank. While this particular system is for a marine application, it could be modified for other uses.
Level Sensor Switches From Clean Liquids to Dry Solid Materials
March 19, 2010 by admin
Filed under Level, Liquid Level
BlueLevel Technologies, Inc. announces the availability of its latest level sensor, the Model CPH Capacitive Proximity Switch for clean liquids and dry bulk solid materials.
Managing Director, Joe Lewis, comments that “this level sensor is a great addition for our customer base. It provides them with a compact level sensor offering reliable performance and a low cost”. It provides level control, level detection and level monitoring capability.
The Model CPH is a capacitive proximity switch consisting of units available to operate with either AC or DC loads. They are compact level sensors, being 30mm in diameter and approximately 80mm deep. They are low in cost, well under $100, and provide a very high performance-to-cost value ratio.
The Model CPH 2-wire AC proximity switch operates with voltages from 20-250VAC, switching loads as high as 300ma. These AC capacitive proximity level switches include built-in ESD protection and operate over a wide temperature range from -25°C to +70°C (-13°F to +158°F).
The Model CPH 4-wire DC proximity switch units are capable of interfacing with a wide variety of PLC’s, operating on voltage from 10-30VDC, and come in either NPN or PNP styles with both NO and NC wiring connectivity.
BlueLevel Technologies brings 35 years of process measurement and control experience and knowledge to its “Just Level” service strategy. “Just Level” is designed to anticipate, meet and exceed the needs of BlueLevel Technologies customers and their industries by bringing decades of process measurement and control expertise directly to the user. Level measurement and monitoring is our single focus and our passion.
Sensor Measures Dissolved Nitrate In Water
March 2, 2010 by admin
Filed under Level, Liquid Level, Temperature
Featuring a precision nitrate ISE electrode sensor with an integral self-cleaning sprayer, the new HYDRA Nitrate Analyzer System from Electro-Chemical Devices, Inc. (ECD), offers superior measurement, monitoring and control with virtually no maintenance.
The highly intelligent HYDRA Nitrate Analyzer System measures the concentration of dissolved nitrate as nitrogen (NO3–N) in water. The sensor uses two electrodes to determine the NO3–N concentration: a nitrate ion electrode and a chloride ion electrode. An optional electrode is also available for pH measurement.
The system’s HYDRA Analyzer is configured to periodically actuate a cleaning cycle using the integral spray cleaner in the nitrate sensor, minimizing the formation of biofilms or other coatings on the electrodes and keeping maintenance to a minimum. The cleaning cycles feature a user configurable period and duration. During the cleaning cycle the 4-20 mA output is held at either a preset value or the last value.
While useful in all types of water treatment applications, the HYDRA Nitrate Analyzer System is especially well suited for municipal wastewater treatment plants. Nitrogen primarily enters a municipal wastewater system as ammonia/ammonium compounds. Nitrification oxidizes the toxic ammonium ion into a much less toxic nitrate ion using an aerobic activated sludge process.
De-nitrification reduces the nitrate ion (NO3-) to nitrogen gas (N2) through an anoxic reaction in the same treatment basin or in a separate anaerobic digester. The NO3–N measurement helps optimize the methanol being fed to the digester, which minimizes cost and provides trend measurement of the total nitrogen (TN) in the effluent.
The nitrate ion electrode provides the primary measurement. A second electrode measures the Chloride ions in the sample. The HYDRA Analyzer subtracts the appropriate amount of signal from the nitrate measurement for accurate monitoring. The sensor also detects temperature, and the analyzer provides a temperature-compensation calculation for superior measurement accuracy.
The rugged nitrate sensor offers 1.25-inch NPT rear facing threads for attaching an extension/immersion tube for easy installation from catwalks or handrails. Internal signal conditioning allows the sensor to be mounted up to 200 meters from the analyzer. The sensor is extremely low-maintenance, featuring a movable electrode guard to facilitate easy electrode replacement when necessary.
ECD’s HYDRA Nitrate Analyzer System measures nitrate and chloride in concentrations from 0.1 to 1000 ppm, pH from 0 to 14 and temperature from 0 to 50°C (32 to 122°F). Accuracy is ±3 percent of reading with a response time of T90 1 minute.
Featuring a backlit LCD display that provides up to 4 lines of text and graphics, the HYDRA Analyzer includes two 4-20 mA outputs with two SPDT alarm relays. Input power is 110/220 Vac. It is housed in a rugged NEMA 4X enclosure.
Medical Sensor Is Put On Blood Bags
January 27, 2010 by admin
Filed under Level, Liquid Level
Schweizer Electronic AG, situated in Schramberg, Germany, and SIEMENS AG Österreich, with registered offices in Vienna, Austria, have agreed to extensive cooperation for the manufacture and marketing of RFID transponders with the integrated sensor technology known as “SEAGSens”. Schweizer Electronic is responsible for the manufacture of the transponders developed in collaboration with the Hochschule Offenburg (Offenburg university) and SIEMENS. SIEMENS will assume the distribution and marketing. The SEAGSens will be used in seamless temperature monitoring, tracing and the clear identification of blood bags, medications or foodstuffs, among others. Schweizer Electronic is to operate the RFID business in the context of a “Schweizer Tracking and Tracing Solutions” business unit.
After having completed extensive tests and pilot projects, Schweizer Electronic has now finalised the qualification of the SEAGSens (see pictures). The first series production order has already been received.
In principle, the RFID-based measuring instrument monitors and verifies temperatures as required in this logistical application of blood products. Reliability is the all-important decisive factor here. The SEAGSens fulfils the highest requirements of clinics and blood banks. The temperature-based quality assessment of donor blood on their entire route from the donor to the patient markedly reduces the discard rate of blood products which leads to considerable cost savings.
In addition, the clear identification of the stored blood effectively prevents the serious consequences of incorrect blood transfusions caused by mistaking blood bags. The same technology can also be used to monitor the transport and logistical processes of other industries and applications for which temperature is of critical importance.
RFID sensor tag SEAGsens on blood bag
To achieve the required quality level of temperature-sensitive pharmaceutic products, monitoring of the complete cold chain has to be ensured. Therefore, Schweizer Electronic designed the requirements for a tracking and tracing system for blood products in close collaboration with Siemens AG Österreich and ‘Universitätsklinik für Blutgruppenserologie und Transfusionsmedizin’ located in Graz.
The complete temperature profile of blood bags has to be monitored from vein of donor to vein of recipient. Thus, the monitoring device must be able to withstand the centrifugation processes necessary for blood fraction (up to 5,000 G) without malfunction. The operation costs per run have to be low.
Together with Siemens AG Österreich and University of Offenburg Schweizer Electronic developed SEAGsens, a temperature data logger with RFID frontend.
How does it work?
A digital sensor is measuring the temperature very accurately at a freely selectable time cycle. The microcontroller is analysing the temperature/time data and stores up to 30,000 measurement readings in a memory chip. The memory can be read out contactlessly at any time via the RFID wireless interface (HF frontend). Schweizer Electronic developed a special housing and battery technology to ensure centrifugation ability. The qualification process and the clinical field test have been terminated successfully. The benefit: monitoring of long periods through high memory and battery capacity.
The SEAGsens RFID sensor tag provides highest level of functionality, safety and quality. Due to the long operation time, costs per run are comparatively low. The integrated battery allows a continuous useability of more than 3 years. The temperature focused quality control reduces the wastage rate of blood products considerably. By the unique identity of each single blood bag, incorrect transfusions with all their harmful consequences are efficiently eliminated.
Liquid Sensor Has No Moving Parts
January 23, 2010 by admin
Filed under Flow, Level, Liquid Level
A precision off-the-shelf liquid level sensor, developed for motorsport, military and industrial applications the ‘R-Series’ is now available from Gill Sensors. The sensor has no moving parts, utilising advanced capacitive technology to accurately monitor the liquid level.
Compatible with fuel, oil, water and other specialist liquids, the R-Series liquid level sensor features an SAE 5-bolt flange mount as standard and is manufactured to the end users’ exact length requirement, avoiding the need for any mechanical adjustment by the user. With fully integrated electronics producing a configurable 0-5V analogue output, the R-Series is seen as an ideal ‘drop-in’ solution for most liquid level applications.
In addition to the standard R-Series sensor, Gill Sensors has also introduced an ‘Rxl’ variant for applications where a very long sensor is required. This variant of the R-Series utilises the same SAE 5-bolt mounting pattern but introduces additional mechanical strengthening features to support the longer probe. This sensor targets industrial applications that require precision liquid level measurement of storage tanks up to 3m in depth, says the company.
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