CAUTION: Never connect a Current sensor directly across a battery or power supply without a resistance component, to limit the current to within the range of the sensor. Failure to limit the current will cause permanent damage to the sensor. 

  • If the Voltage sensor is not part of a complete circuit, then data collected may appear ‘noisy’. To measure voltage accurately, you need an impedance (resistance). The Voltage sensor is a high impedance device and will pick up any electrical ‘noise’. 
  • Note: To demonstrate zero impedance, short out a Voltage sensor by connecting its black & red plugs together.
  • A tare function is present in the software to set the zero of current and/ or voltage.  
  • The Current sensor has a very low resistance so it will introduce as little resistance as possible to
  • the circuit.
  • For some work, the d.c. output from a chemical cell will give the best results, for example discharge and charge constants of a capacitor resistance circuit.   
  • An alternative to batteries is to use a fully isolated mains power supply with a regulated DC output (smoothed and fully rectified).
  • Be aware that some power supplies are 1/2 wave rectified producing an average rather than true d.c. The sensors will ‘pick up’ the fluctuations in voltage and current from this type of power supply. The Voltage and Current sensor does not smooth the data, as you would see in a multimeter, and will return the value that is present at the sample period. Without smoothing, you can record at very short intersample periods (50µs or 50,000 Hertz).   
  • The suitability of components can be checked using Ohms law.
  • When large quantities of cells are used in a circuit, the current flow can cause low value resistors to become very hot (W = V x I). 

For example: A 100 Ω 3 W resistor gives good results without too much heat.

      • 6 V supply with 10 Ω resistor = 0.6 A (600 mA) current flow (Power 0.6 x 6 = 3.6 W).
      • 6 V supply with 50 Ω resistor = 0.12 A (120 mA) current flow (Power 0.12 x 6 = 0.72W).
      • 6 V supply with 100 Ω resistor = 0.06 A (60 mA) current flow (Power 0.06 x 6 = 0.36W).

  • The Current sensor is protected to a voltage of ±13 V, so as long as the voltage on its inputs are below this value, the sensor will not be damaged. The maximum working voltage of the Current sensor is ±13 V. 
  • The operating range of the sensor is 0 to 40 ̊C and 0 to 95% RH (non-condensing). Do not subject to extreme heat or cold. Do not expose to direct sunlight for extended periods of time.
  • The sensor is not waterproof. It may be cleaned using a damp cloth. Do not immerse in water or detergent. Do not place the sensor in an environment in which high humidity levels are possible as this may result in damage or malfunction.