Ouputs in Engineering Units
The readout is supplied with communication cable and host software allowing you to connect it to a PC, which means you can program the readout to display engineering units. For example, the Vibrating Wire VW2106 model has up to 254no. sensor locations within its on board memory. However in order to activate this function, there is some pre-programming to be done. This can either be done on the readout itself or using the host software. Depending on which calculation you are using, whether it be Linear or Polynomial, there are numbers be to filled in which are provided on the calibration sheets from each sensor you plan to read with the readout. Once this is programmed it is also capable of storing the live reading of the sensor you are connected to with the press of a button.
A selection of Engineering units available
- μStrain = Strain gauges
- mm = Displacement gauges
- kPa, bar, psi = Total Pressure Cells, Piezometers
- mH2O = Piezometers
The readout also has an input for the thermistor from any VW sensor. Although these output resistance, the readout already has the Steinhart Coefficients plugged into it which enables it to present the readings in °C or °F.
This can be an essential feature for fault finding. Sometimes if you are not able to get a reading at all you can determine the significance of the problem by listening to the wire being excited by the readout every 2 seconds. What you should hear is a nice clear 'ping' when the wire is excited, with no distortion in the sound. Clarity in the sound is key, if there is something wrong with the sensor it can generally be heard.
This is particularly of use for Load Cells as these have multiple Vibrating Wire sensors along the same cable. The readout contains a Multiplexer which cycles through 6 channels making it ideal for 6 gauge load cells. It will take a reading from each gauge then present the average. When storing to memory it also saves the readings from each gauge to ensure you are actually getting a reading from each gauge which assists in determining whether there is a fault with any sensor.
Sprung Grabber Set
Geosense provide the VW2106 with its own Sprung grabber set to make connecting to sensors even easier. Sometimes, using the terminal block on the readout can get rather fiddly so this set allows you to leave the wire connected to the terminal block then grab on to the bare wires of the sensor using the grabbers.