Sensor Configuration VW108 Vibrating Wire by Keynes Controls
The following page demonstrates the setting up and testing of a vibrating wire settlement cell onto a VibWire-108 sensor interface. The vibrating wire sensor interfaces can all operate in Hz, Digits and SI Units.
The 8 channel units can mix the output measurement types between Hz, Digits and SI units for any output.
The example uses an Encardio Settlement Cell for the sensor, and the polynomial sensor coefficients taken from the manufactures sensor calibration data sheet. The quadatic equation calibration factors are used.
The Keynes Controls google test sheet is used to check the calibration factors and to predict what the instrument will display for a pre-determined sensor frequency. The test sensor used by by Keynes operates at 2450.6 Hz - 6451.6 Digits.
All of the Keynes Controls vibrating wire sensor interfaces follow the same procedure for configuring sensors.
The parts used are: 1 x VibWire-108-485/MODBUS, 1 x USB-485-Pro media converter and the QLOG Software.
Selecting the Calibration Factors
The Sensor Configuration VW108 Vibrating Wire by Keynes Controls will be set to supply vibrating wire sensor readings directly is SI Units. The SI units shown in the example are in units m wc. Care has to be taken to ensure the correct order for the factors A, B and C are identified and used.
Different sensor manufacturers assign different meaning for the calibration factors.
The Window opposite is from the Keynes QLOG Application Software.
Setting Channel 0 into SI units
Chan 0 Frequency Output = 2 0 = Hz 1 = Digits 2 = SI Units
Temperature Sensor Settings
Chan 0 Therm no = 1 The industry standard Steinhart-Hart calibration factors are preset.
The most common temperature calibration factors are preset into the instrument. The user can adjust the configuration parameters for any new sensors.
Vibrating Wire Calibration Factors
The calibration factors used in this example are taken from the sensor calibration sheet shown above. Select the image to zoom in.
Based on equation
Output SI Units = C(F²) + BF + A - D(T₀-T) + (S₀-S) - quadratic equation
The factors (S₀-S) - initial sensor conditions - offset only and is frequently ignored as they only effect the offset.
Instrument QLOG Configuration
Quadratic Sensor factors used by the instruments
The example is using the VW sensor quadratic factors
A = Offset Term
B = Linear Term
C = Quadratic Term
D = Thermal expansion
Application Software
The applications software enables real-time measurements to be made and displayed into a series of charts and panel meter displays.
The QLOG software that is supplied with the sensors is used to fully configure the sensors and multiparameter systems.
ARGES Turbidity, Tryptophan, ARGES Ammonia, ARGES Ammonium, ARGES Hydrocarbon, PAH, Poly Aromatic Hydrocarbon, Dissolved Oxygen, ARGES pH, ARGES Potassium, rivers, streams, ditches, cuts, culverts, dykes, sluices, sewers, multiparameter, SONDE