Aalborg Dfc26S-Van5-C5-3Ca-01-Ss, Dfc Thermal Mass Flow Controller

Aalborg Dfc26S-Van5-C5-3Ca-01-Ss, Dfc Thermal Mass Flow Controller

USD 1481.00

In stock

4.6 stars, based on 78 reviews

Aalborg, DFC26S-VAN5-C5-3CA-01-SS, DFC Thermal Mass Flow Controller Stainless Steel, Viton-A Seals, 1/4" Compression, No Display, +15 VDC, 0-5 VDC/ 0-5 VDC, RS485, Carbon Dioxide CO2 0-10 mL/Min, 14.7 psia Metering Pressure, 21.1 Deg C / 70 Deg F Temperature DFC digital mass flow controller Controller can be programmed for various control functions including flow set point, totalizer, stop totalizer, read totalizer, totalizer from preset flow, stop at preset total, auto zero, and more

A Wheatstone bridge design is used to monitor the temperature dependent resistance gradient on the sensor windings which is linearly proportional to the instantaneous rate of flow

Alarm conditions are reported via the digital interface or can activate the contact closure outputs

An on-board microprocessor and nonvolatile memory store all calibration factors and directly control a proportionating electromagnetic valve

Auto Tune The Auto Tune function allows the DFC to automatically optimize control response for the gas under actual process conditions

Auto Zero The DFC automatically nulls the sensor zero offset whenever the flow set point is below 2 of full scale

Balanced Power Supply The DFC operates on plusmn 15 VDC

Both flow conduits are designed to ensure laminar flows and therefore the ratio of their flow rates is constant

Contact Closure Programmable via the digital interface such that the relays can be made to switch when a specified event occurs e.g

Conversion Factors Conversion factors for up to 256 gases are stored in the DFC

Conversion factors may be applied to any of the ten gas calibrations via digital interface commands

Deviations from the set point are corrected by compensating valve adjustments, with PID algorithm thus maintaining the desired flow parameters with a high degree of accuracy

Digital interface commands are provided to Set the totalizer to Zero Start/Stop totalizing the flow Read the totalizer Start the totalizer at a preset flow Stop the flow at a preset total Multi-Gas Calibration The DFC is capable of storing primary calibration data for up to 10 gases

Engineering Units The flow set point, measured gas flow and associated totalizer data is scaled directly in engineering units via digital interface commands

Flow Alarms High and Low gas flow Alarm limits are programed using the digital interface

Interface The digital interface operates access to applicable internal data including Flow Set Point, Actual Flow, Zero Adjustments, and linearization Table Adjustments

Maximum power consumption is 13.5 watts at plusmn 15 VDC.

Principles of Operation Metered gases are divided into two laminar flow paths, one through the primary flow conduit, and the other through a capillary sensor tube

Programmable Flow Aalborg software supports programmable flow modes, allowing execution of custom programming of up to ten steps

Provisions are made to either disable, force or store the current auto zero via digital commands

Self Diagnostics Whenever power is first applied, the DFC runs a series of Self Diagnostic Tests to ensure that it is in optimum working condition

The current requirements for the positive and negative power supplies are balanced such that the current in the power supply common connection is minimized

The digital closed loop control system continuously compares the mass flow output with the selected flow rate

The following units of measure are supported of FS, mL/min, mL/hr, SCFM, SCFH, sL/min, sL/hr, lbs/hr, lbs/min, and one user defined unit of measure

The output of the Wheatstone bridge is converted to digital format with a 12 Bit ADC analog to digital converter

The resultant temperature differential is proportional to the change in resistance of the sensor windings

The total mass of gas is calculated by integrating the actual gas flow rate with respect to time

This feature allows the same DFC to be calibrated for multiple gases while maintaining the rated accuracy on each

To accommodate this feature the control valve must fully close under that condition

Totalizer The firmware for the DFC provides functions to register total gas quantity

Two precision temperature sensing windings on the sensor tube are heated, and when flow takes place, gas carries heat from the upstream to the downstream windings

Valve Override Means are provided to force the control valve fully open purge or fully closed via either the analog or digital interfaces

Various flow configurations include ramping, linearized increasing and decreasing modes

When a low or high flow alarm limit is exceeded or when the totalizer reaches a specified value