Ebtron Thermal Dispersion ATMD Technology

Ebtron Airflow Temperature Measurement Devices (ATMD) employ Thermal Dispersion Technology that relates the velocity of the air to the power and rise in temperature of a heated element in a moving air stream. EBTRON uses precision, bead-in-glass thermistor probes to measure the airflow rate and air temperature. Multiple sensing points are used to produce an average velocity for true volumetric airflow (CFM/LPS). Each individual sensor node is calibrated to NIST traceable airflow standards at 16 points resulting in a sensor accuracy of 2% of reading.

Unlike velocity pressure-based Pitot arrays, probes or other pressure-based devices that have very little sensitivity at low air velocities and use percent of full scale pressure transducers, EBTRON's sensitivity to airflow increases as the flow rate decreases and accuracy is percent of reading. Greater sensitivity results in better accuracy, especially with turn-down, compared to differential pressure-based devices. As a result, the technology is ideal for the measurement of the relatively low airflow rates typically found in HVAC applications. Long term stability is ensured by the selection of high quality bead-in-glass thermistor probes and signal processing components. Unlike pressure-based devices that frequently require field calibration and auto-zeroing, EBTRON does not recommend periodic calibration of its airflow measuring devices 1. In fact, there is no auto-zero function in any EBTRON flow measuring device. It simply is not required.

Best Sensitivity at Low Flow

• Ebtron advanced thermal dispersion measurement technology results in a dramatic sensor sensitivity increase as airflow velocity decreases as shown in the accompanying illustration.
  
  
• Each sensor is calibrated at up to 16 airflow rates. All calibration starts from still air. A large signal change with airflow results in accurate airflow measurement, even at low airflows. A microprocessor-based transmitter reads calibration data stored in a memory chip in the sensor probe cable connector plug and “flashes” it into memory during transmitter power up making all EBTRON products “plug and play”.
  
  
• The transmitter essentially reverses the calibration process in the field. Each sensor pair is individually read by the transmitter. The measurements are summed and divided by the number of sensor points. A high speed microprocessor results in virtually instantaneous measurement. As a result, EBTRON technology is ideal for the direct measurement of outside airflow rates and flow tracking applications.
  
  
• In addition, the transmitter is able to detect errors and ignore sensors if a sensor or cable gets damaged. As a result, your system is always running.