Features and Benefits:
- Automatic Zeroing. The automatic zeroing circuit eliminates all output signal drift due to thermal, electronic or mechanical effects, as well as the need for initial or periodic transmitter zeroing. For transmitters operated in temperature-controlled spaces (with no thermal effect upon span), this automatic zeroing function essentially produces a “self-calibrating” transmitter. The automatic zeroing circuit will re-zero the transmitter to within 0.1% of its operating span; for a transmitter with a 0.02 IN w.c. operating span, this represents a zeroing capability within 0.00002 IN w.c. To permit manual calibration of the VELTRON II, an electronic switch is provided to permit manual positioning of the zeroing valve.
- Accuracy. The VELTRON II is designed to maintain an accuracy of 0.1% of Natural Span. For a span of 0 to 0.05 IN w.c., this accuracy is equivalent to an output accuracy of ±0.00005 IN w.c. differential pressure or 0.45 FPM velocity at span.
- Continuous Display of Process. All VELTRON II’s are equipped with a 2×20 liquid crystal display (LCD) for use during the configuration and calibration process, and to display one transmitter output during normal operating mode. The VELTRON II offers an optional multi-line, backlit, graphical LCD providing up to four lines of data display, with each line individually scalable in user selectable format and units of measure. For high visibility, the main process variable (flow) is displayed with easy-to-read, triple-size digits. Other process variables are displayed with standard size digits.
- Analog Communication. Each analog input and output signal can be individually configured for 0-5VDC, 0-10VDC, or 4-20mADC by means of a single jumper.
- Electronic Respanning. The VELTRON II operating span can be electronically selected anywhere between the Natural Span and 40% of Natural Span, without having to perform recalibration involving an external pressure source.
- Primary Signal Noise Filter. To eliminate background noise and pulsations from the flow signal, the VELTRON II is equipped with a user selectable digital low pass filter.
- High Turndown Ratio Operation. The VELTRON II, with its high level of accuracy and automatic zeroing circuitry, can maintain linear output signals on applications requiring velocity turndown of 10 to 1 (equal to a velocity pressure turndown of 100 to 1).
- Microprocessor Based Functionality. The VELTRON II’s on-board microprocessor performs the functions of operating parameter selection, transmitter configuration, input/output and display signal scaling, and transducer calibration. Imbedded software performs span, flow, and 3-point “K” factor calculations. Input to the micro-processor is via pushbutton.
- AUTO-purge Management (optional). For “dirty air” applications requiring the use of an Air Monitor AUTO-purge system, the VELTRON II provides the capabilities of establishing purge frequency and duration while giving the user a choice of either internally timed cycle frequency or externally triggered purge initiation. During the purge cycle all transmitter outputs are maintained at their last value prior to the start of the purge cycle.
- Special Functions and Alarm Capability. The VELTRON II is capable of performing one of five special application functions using a second transmitter as an input: Summed flow, flow differential, low signal select, high signal select, or percent deviation. The special function output can be both displayed and provided as an analog output signal. Alarms related to the measured process can be configured for one of three modes: Low/Low, High/Low, and High/High.
- Multiple Operating Power Selections. Standard input power supplied to the VELTRON II can be either 24VAC or 24VDC via automatic selection. An optional 120VAC external power transformer (UL listed) can be provided.
- NEMA 1 Enclosure Rating.
- CE Certification. For optional CE Certification, the VELTRON II is furnished in a NEMA 4 enclosure.