Basic Explanation of Overloads

Posted by Aaron on 7 August 2015

During acquisition in the Framework software users will sometimes observe overloads (red or orange data points) indicating that the instrument is in an undesirable state.  When an overload occurs one of 5 indicators will switch on, showing a red or orange box at the bottom of the experiment runner window with a message indicating which overload state has happened.  At the same time the data points will turn red or orange for the overloaded points.  Here is a basic explanation of the different types of overloads:

I OVLD Indicates a current overload.  Sample area may be too big or the battery/supercap/fuel cell generates too much current for the potentiostat hardware.

V OVLD Indicates a voltage overload.  The battery/supercap/fuel cell voltage is too high to measure, or the electrometer is disconnected and has drifted to the rails.  Double-check that the white and blue leads are connected properly.

CA OVLD Indicates a control overload.  The potentiostat cannot supply enough current between working and counter leads to reach the desired potential at the working electrode.  The blue or white lead could be disconnected, or the cell’s uncompensated resistance is so high that the instrument reaches its compliance voltage.

I ADC Indicates that the I channel A/D converter is railed.  Incorrect instrument settings were used during an EIS scan.  The state of the cell may be changing too much during the AC measurement to get a valid reading.

I VDC Indicates that the V channel A/D converter is railed.  Incorrect instrument settings were used during an EIS scan.  The state of the cell may be changing too much during the AC measurements to get a valid reading.