The Little Dipper™ 2 may be purchased as a sensor integrated with control boxes from third party vendors, in which case the calibration instructions in our user manual cannot be used to calibrate or set a new range for control box wired sensors. Refer to the control box’s manual for calibration instructions.
Every control box will have its own specific procedure for calibrating integrated sensors. The following is a general procedure for calibrating your control box integrated sensor:
Make sure the control box is powered on and power is getting to the sensor.
Put your hand in front of the sensor and look at the response displayed on the control box display; the response should increase as your hand gets closer to the sensor’s optical head and vice versa.
Enter the control box’s calibration mode.
Put the sensor in blank solution or source water that does not contain the fluorophore of interest.
Using control box commands set the blank.
Put the sensor in a solution with a known concentration of the fluorophore of interest.
Using control box commands input the concentration value of the standard solution being measured.
Using control box commands set the standard solutions response.
Make sure the settings for this sensor calibration are saved.
Now you can read both blank and standard solution and the control box should display actual concentration values for those solutions read.
It is recommended that a final check be made after the unit is calibrated. To make this check you will need to dilute your standard solution by half using your blank solution or source water.
Simply fill a container half full with your standard solution and add approximately the equivalent volume of blank solution or source water to your standard solution. Ensure that the container used is dark like a glass beaker wrapped with black electrical tape. It is not recommended to use plastic milk jugs as that can cause the sensor on the device to be interfered with.
Stir the solution and read it using your calibrated sensor. The control box should display approximately half of the calibration value set during the calibration procedure.