Make: Projects

Using Arduino to Create an Online Reactor Reactivity Meter

A Digilent microcontroller board is used to perform inverse-kinetics on an input signal from neutron detectors. Current or pulse detectors can be used, but signal conditioning to obtain a signal of 0-3.3V is required. The setup only works on one range.

  • By
  • Time Required: 3 hours
  • Difficulty: Moderate
Using Arduino to Create an Online Reactor Reactivity Meter

Inverse-kinetics is an equation that will calculate the reactivity value for the reactor (in terms of cents). The meter should start when the reactor is critical.



Step #1:

Using Arduino to Create an Online Reactor Reactivity Meter
  • To change the signal from a current chamber use a picoammeter or current amplifier. There is usually an analog voltage output for the range. The signal is usually inverted. Invert the signal using an op-amp.
  • For a pulse detector us a rate meter to obtain an output voltage. Some resistors may be required to change the 0-10V output to 0-3.3V.
  • Program the micro-controller to sample the voltage. Filtering the data is recommended
  • Use the inverse-kinetics equation to determine reactivity.
  • Filtering the reactivity output is also recommended.
  • For my project I sent the data out to an OLED screen for display and I also sent it to LabView where it can be stored.


The code is attached in the documents. An additional header file was used to change a float to string. I got the header file from the Arduino playground. I'm sure there is a better way to do it but I couldn't figure it out because I'm new to C++. I also attached a picture of the labview program. The output from the micro-controller to the computer uses a comma to separate the reactivity value and timestamp.

  • Alessandro

    Dear Friend, I would like to know how to get more detail about this project. Thanks