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Dry Material (Powders) Level Sensing Devices Specifications

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Device Classification




   Device Classification       
   Your choices are...
 
      
 
   Sensor-Only
 
     By definition, a sensor is a transducer, its output is meant for processor, controller or data acquisition system. No display or user interface is present. If you desire a switch, choose this option.
 
   Sensor System
 
     By definition, a sensor system has more capability than a transducer. The unit may have a display and/or a user interface. If you desire a simple gauge, a locally programmable unit (stand-alone) or a controller / totalizer, choose this option.
 
   Search Logic:      All products with ANY of the selected attributes will be returned as matches. Leaving all boxes unchecked will not limit the search criteria for this question; products with all attribute options will be returned as matches.
Level Measurement Type




   Level Measurement Type       
   Your choices are...
 
      
 
   Continuous Level
 
     Device measures level within a specified range, output gives a continuous reading of level.
 
   Point Level / Multi-Point Levels
 
     Device marks a specific level, generally used as high alarm or switch. Multiple point sensors can be integrated together to give a stepped version of continuous level.
 
   Search Logic:      All products with ANY of the selected attributes will be returned as matches. Leaving all boxes unchecked will not limit the search criteria for this question; products with all attribute options will be returned as matches.
Measuring Range




   Number of Switch Points
 
     The level sensing device has a series of switches along the probe. When the material is present this causes the switch to activate.
 
   Search Logic:      User may specify either, both, or neither of the "At Least" and "No More Than" values. Products returned as matches will meet all specified criteria.
   Measuring Range
 
     The level range that devices can measure.
 
   Search Logic:      User may specify either, both, or neither of the limits in a "From - To" range; when both are specified, matching products will cover entire range. Products returned as matches will meet all specified criteria.
           
   Allowable Sensor Over-Range
 
     Overrange specification limits the range of matching products to the specified range multiplied by a selected overrange factor. This keeps returned matches close to the range requirement and filters out products with a wider range than needed. "From", "To", and "Overrange" must all be specified to activate this option.

Example: User specifies a sensor with a range from 0-100. Without overrange specification, sensors with ranges of 0-100, 0-1000, and -10,000 to +10,000 are returned as matches. An overrange specification of 50% will filter out any sensors with a full scale range greater than 150.
 

   Search Logic:      Matching products will have a range within the specified overrange limit.
Output Options




   Output Options       
   Your choices are...
 
      
 
   Analog Voltage
 
     The output is an analog voltage signal.
 
   Analog Current
 
     Output signal is a current, representing level.
 
   Frequency or Modulated Frequency
 
     Frequency or modulated frequency output (e.g., sine wave, pulse train, AM, or FM)
 
   Search Logic:      All products with ANY of the selected attributes will be returned as matches. Leaving all boxes unchecked will not limit the search criteria for this question; products with all attribute options will be returned as matches.
Field Adjustable Performance




   Field Adjustable Measurement Ranges?
 
     Different ranges can be selected while devices are in the field.
 
   Search Logic:      "Required" and "Must Not Have" criteria limit returned matches as specified. Products with optional attributes will be returned for either choice.
Process Operating Conditions




   Maximum Operating Pressure
 
     Maximum pressure environment device is rated for.
 
   Search Logic:      All matching products will have a value greater than or equal to the specified value.
   Material Temperature Range
 
     Maximum material temperature device is rated for.
 
   Search Logic:      User may specify either, both, or neither of the "At Least" and "No More Than" values. Products returned as matches will meet all specified criteria.
   Material Density:
 
     Material Density listed is the maximum material density.
 
   Search Logic:      All matching products will have a value less than or equal to the specified value.
Meter Technology




   Meter Technology       
   Your choices are...
 
      
 
   Differential Pressure Sensors
 
     Differential pressure sensors measure head pressure in a vessel based on the height of the media.
 
   Ultrasonic / Sonic
 
     Ultrasonic or sonic devices measure the length of time it takes for a reflected sound wave to return to a transducer. Transmitted time is proportional to level.
 
   Radar / Microwave
 
     Radar or microwave devices send a microwave pulse toward the process material. The pulse is reflected back by the material's surface and detected by the receiver. The level is inferred from the time of flight.
 
   Optical
 
     Optical devices use optic sensors and the principle of optical reflection to detect the presence or absence of fluid. Typically, light emitting diodes (LEDs) are used as the light source. 
 
   Pressure Membrane
 
     Pressure membrane meters have a pressure-sensitive switch. They transmit pressure to an internal sensor via an organic or thin-metal membrane.
 
   Electrical Conductivity or Resistance
 
     Electrical conductivity or resistance-based devices use a low-voltage power source applied across separate electrodes. A conductive liquid which contacts both probes completes a conductive circuit.
 
   Capacitive / RF Admittance
 
     Capacitive or RF admittance devices use a radio frequency (RF) technique that is based on differing dielectric constants. The impedance from the RF signal changes whenever the material approaches the sensing region.
 
   Air Bubbler
 
     Air bubblers feed a gas (usually air) at constant volumetric rate through a bubble tube submerged in a liquid. The amount of pressure needed to force the bubble from the bottom of the tube is equal to the hydrostatic pressure at that point.
 
   Mechanical / Magnetic Floats
 
     Mechanical devices or magnetic floats use sealed reed switches in a stem with a permanent magnet installed in the float. As the float rises or falls, the switch is activated.
 
   Rotation Paddle
 
     Device uses a small electric motor drives a paddle, which rotates freely in the absence of material. When the paddle is impeded by material, the motor senses this and typically triggers a switche(s).
 
   Radio Frequency
 
     Radio frequency (RF) devices emit a high-frequency/low-power radio signal from a probe. When the material contacts the probe, the bridge becomes unbalanced and a comparing circuit realizes the change. This causes a relay output to change state.
 
   Vibrating / Tuning Fork Method
 
     Tuning forks use various technologies (typically piezoelectric) to vibrate a probe and then constantly monitor the presence or absence of that vibration.
 
   Other
 
     Other unlisted, specialized, or proprietary meter technology.
 
   Search Logic:      All products with ANY of the selected attributes will be returned as matches. Leaving all boxes unchecked will not limit the search criteria for this question; products with all attribute options will be returned as matches.
Communication Interface Options




   Communication Interface Options       
   Your choices are...
 
      
 
   Serial Interface
 
     Serial communication protocol such as RS232, RS485, USB.
 
   Parallel Interface
 
     Parallel interfaces use a parallel communication protocol such as general-purpose interface bus (GPIB).
 
   Other
 
     Devices use other, unlisted communication interfaces (e.g., modems, RF transmitters).
 
   Search Logic:      All products with ANY of the selected attributes will be returned as matches. Leaving all boxes unchecked will not limit the search criteria for this question; products with all attribute options will be returned as matches.
Mounting Options




   Mounting Options       
   Your choices are...
 
      
 
   Side mount
 
     The device mounts on the side of the vessel which contains the media to measure.
 
   Top mount
 
     The device mounts on top of the vessel which contains the media to measure.
 
   Bottom mount
 
     The device mounts at the bottom of the vessel which contains the media to measure. 
 
   Search Logic:      All products with ANY of the selected attributes will be returned as matches. Leaving all boxes unchecked will not limit the search criteria for this question; products with all attribute options will be returned as matches.
Instrument (Sensor System) Only Options




   Instrument Display Options:       
   Your choices are...
 
      
 
   Nonelectrical visual or audio output
 
     The display has a non-electrical visual indicator such as simple float, or an audible click.
 
   Analog Meter or Indicator
 
     The display has an analog meter (typically with a needle), or uses LED indicators.
 
   Digital Readouts
 
     The device displays numerical or application-specific readouts.
 
   Video Display Terminal (VDT)
 
     Video display terminals (VDT) include cathode ray tubes (CRT) and flat panel displays (FPD).
 
   Search Logic:      Products with the selected attribute will be returned as matches. Leaving or selecting "No Preference" will not limit the search criteria for this question; products with all attribute options will be returned as matches.
   Instrument User Interface Options:       
   Your choices are...
 
      
 
   Analog Front Panel
 
     Has analog user inputs such as potentiometers, dials, switches, etc.
 
   Digital Front Panel
 
     Setup or program through the front panel using digital keypad & displays, menus, etc.
 
   Computer Controllable
 
     The device can be controlled remotely via a computer interface.
 
   Search Logic:      Products with the selected attribute will be returned as matches. Leaving or selecting "No Preference" will not limit the search criteria for this question; products with all attribute options will be returned as matches.
Features




   Sanitary Applications rated (3A, etc.)?
 
     Devices are rated for sanitary applications such as those found in the pharmaceutical and food processing industries.
 
   Search Logic:      "Required" and "Must Not Have" criteria limit returned matches as specified. Products with optional attributes will be returned for either choice.
   Can handle liquids with suspended solids (slurries)?
 
     Device can handle slurries, such as sewage water/ waste water.
 
   Search Logic:      "Required" and "Must Not Have" criteria limit returned matches as specified. Products with optional attributes will be returned for either choice.
   Built in alarm indicator?
 
     Devices have a built-in audible or visual alarm that is more than a switch or relay closure.
 
   Search Logic:      "Required" and "Must Not Have" criteria limit returned matches as specified. Products with optional attributes will be returned for either choice.
   Programmable?
 
     Device can be programmed for different ranges, materials, outputs, etc.
 
   Search Logic:      "Required" and "Must Not Have" criteria limit returned matches as specified. Products with optional attributes will be returned for either choice.
   Recorder / Totalizer Functions?
 
     Records and/or totalizes or integrates measured values (data logger).
 
   Search Logic:      "Required" and "Must Not Have" criteria limit returned matches as specified. Products with optional attributes will be returned for either choice.
   Controller Functions?
 
     Has/takes sensor input, provides control function (Limits, PID, logic, etc.) and outputs a control signal.
 
   Search Logic:      "Required" and "Must Not Have" criteria limit returned matches as specified. Products with optional attributes will be returned for either choice.
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