Description
Some Gamry data files include a column labeled Over with units of bits. This data column indicates an unusual and potentially serious overload condition was present during that data point.
The overload column consists of a string of 13 characters. If no overloads are detected during data acquisition, all of these characters are periods ("."). Any character that is different from a period indicates that an overload occurred at that data point. An example is shown below, with each data column separated by tabs.
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The position of the character in the string indicates the type of overload, not the character. For example, an "h" in the 4th position and an "h" in 6th position indicate different kinds of overload conditions! |
An example is shown below. As with all tables, the columns are <tab> delimited.
CURVE TABLE 1860
Pt T Vf Im Vu Sig Ach IERange Over
# s V vs. Ref. A V V V # bits
0 5 4.20055E+000 1.09180E-004 0.00000E+000 4.20000E+000 0.00000E+000 9 ....ih..i..
1 10 4.20064E+000 1.08839E-003 0.00000E+000 4.20000E+000 0.00000E+000 10 ......s.i..
2 15 4.20065E+000 1.54989E-003 0.00000E+000 4.20000E+000 0.00000E+000 11 ........i..
3 20 4.20066E+000 1.48236E-003 0.00000E+000 4.20000E+000 0.00000E+000 12 ...........
4 25 4.20065E+000 1.41938E-003 0.00000E+000 4.20000E+000 0.00000E+000 11 ...........
5 30 4.20065E+000 1.42771E-003 0.00000E+000 4.20000E+000 0.00000E+000 11 ...........
6 35 4.20065E+000 1.42553E-003 0.00000E+000 4.20000E+000 0.00000E+000 11 ...........
7 40 4.20066E+000 1.42445E-003 0.00000E+000 4.20000E+000 0.00000E+000 11 ...........
8 45 4.20065E+000 1.42343E-003 0.00000E+000 4.20000E+000 0.00000E+000 11 ...........
In this example, overloads were detected for the first three measured data points. From point #3 on, each of the 13 characters is the ".", indicating that no further overloads were recorded anymore. The position of the character in the string indicates the type of overload. Their meanings are listed in the table below:
Position |
Character |
Meaning |
Possible cause/troubleshooting |
|---|---|---|---|
1 |
t |
Timing problem |
Data rate is too fast. |
2 |
e |
Potential overload (electrometer hardware limit exceeded). |
Cell voltage is too big to measure. |
3 |
c |
CA Overload (Control Amplifier hardware limit exceeded). |
Potentiostat is oscillating or potentiostat cannot control the cell potential or current. |
4 |
h |
CA Overload sometime during the data point (History CA Overload). |
Transient overload, CA speed not optimized. |
5 |
i |
I Overload (I/E converter hardware limit exceeded). |
Wrong I/E range. |
6 |
h |
I Overload sometime during the data point (History I Overload). |
Current spike or transient. |
7 |
s |
Settling problem, hardware-related. Some hardware relay or range had not settled to its final position when the data point was taken. |
Experiment is too fast to autorange I/E at these current levels. |
8 |
s |
Settling problem, software-related. Either the operator or the Explain script triggered a data point before the hardware was in a stable state. |
Revise script or retrain operator. |
9 |
i |
ADC input was out of range for a current (I) measurement. |
Wrong I channel range or offset. |
10 |
v |
ADC input was out of range for a voltage (V) measurement. |
Wrong V channel range or offset. |
11 |
a |
ADC input was out of range for a measurement of the auxiliary ADC input. |
Wrong Aux channel range or offset. |
12 |
r |
Raw data overrun. Raw data queue is filled. |
Host computer is too busy or too slow for this experiment. |
13 |
q |
Processed data overrun. Processing queue is filled. |
Host computer is too busy or too slow for this experiment. |