Potentiostatic - Setup Parameters (page 2)

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Potentiostatic - Setup Parameters (page 2)

Description

Second setup page of the Potentiostatic experiment. Press OK to continue or Cancel to go back to the first setup page.

 

3 - PWR Potentiostatic - page 2

 

Parameter

Description

Units

Voltage

The constant voltage applied to the working electrode during the measurement.

volts (V)

Max Current

Max Current controls the current measurement range if I/E Range is set to Fixed mode. If I/E Range is set to Auto mode, Max Current specifies the maximum expected starting current.

 

To avoid overloading the instrument (so you can accurately track the total charge passed), set Max Current to a value below the instrument's maximum current capabilities.

 

Gamry tip bulb

Refer to the potentiostat's Operator's Manual for detailed information on the maximum current limit.

amperes (A)

Max Time

Specify the maximum time of the experiment. The first field specifies the value. Select the unit from the drop-down list.

seconds (s), minutes (min), hours (hr), days (d)

Sample Period

The spacing between data points. The shortest Sample Period we recommend is 0.5 s (50 ms). The longest Sample Period allowed is 715 s for Reference potentiostats and 750 s for Interface potentiostats.

 

Use Sample Period to determine the Number of Points in the data curve as follows:

 

 

The Number of Points must be less than 262 143 (218 - 1). If you have more points, the experiment aborts just before the data acquisition phase of the sequence. The resolution in the Total Time is controlled by the Sample Period. Times that are not integer multiples of the Sample Period are rounded down. For example, if the Sample Period is set for 8 seconds, and a Total Time of 900 seconds is requested, the actual Total Time will be 896 seconds, which is 112 Sample Periods.

seconds (s)

Stop At Threshold

The time tolerance of the Stop At conditions. A Stop At condition must be true for at least the set duration before the experiment ends.

 

For example, if the threshold is set to 5 s and Stop At 1 is set to |Voltage| > Limit of 4.2 V, the cell voltage must exceed 4.2 V for a minimum of 5 s for the experiment to end. Set the threshold to 0 s if you want the experiment to end immediately after a Stop At condition is met.

seconds (s), minutes (min), hours (hr), days (d)

Stop At 1

Specify various limits to an experiment. Choose a limit criterion from the drop-down list and enter a limit value. The unit automatically updates according to the criterion. The limit, if met, causes the experiment to skip to the next step, or stop if there is no subsequent step.

 

Most experiments have Stop At 1 and Stop At 2 criteria. These parameters are treated equally, and if both are used, they are both tested on every raw data point. If either limit is reached, the experiment skips to the next step or stops entirely.

 

Gamry tip bulb

Different experiments allow different tests, but the principles that govern their behavior are the same.

 

The available stop tests are:

•None

oNo stop test is specified. The experiment runs until the maximum specified time is reached.

 

•Voltage

oVoltage < Limit

Stop if the measured voltage is less than the value entered in volts (V).

oVoltage > Limit

Stop if the measured voltage is greater than the value entered in volts (V).

o|Voltage| < Limit

Stop if the absolute value of the measured voltage is less than the value entered in volts (V).

o|Voltage| > Limit

Stop if the absolute value of the measured voltage is greater than the value entered in volts (V).

o|dV/dT| < Limit

Stop if the absolute value of the measured voltage change rate is less than the value entered in V/s.

o|dV/dT| > Limit

Stop if the absolute value of the measured voltage change rate is greater than the value entered in V/s.

 

•Current

oCurrent < Limit

Stop if the measured current is less than the value entered in amperes (A).

oCurrent > Limit

Stop if the measured current is less than the value entered in amperes (A).

o|Current| < Limit

Stop if the absolute value of the measured current is less than the value entered in amperes (A).

o|Current| > Limit

Stop if the absolute value of the measured current is greater than the value entered in amperes (A).

o|dI/dT| < Limit

Stop if the absolute value of the measured current rate of change is less than the value entered in A/s.

o|dI/dT| > Limit

Stop if the absolute value of the measured current rate of change is greater than the value entered in A/s.

 

•Temperature

oTemp > Limit

Stop if the measured temperature is greater than the value entered in degree Celsius (°C).

o|dTemp/dt| > Limit

Stop if the absolute value of the measured temperature change is greater than the value entered in °C/min.

 

•Charge and Energy

o|Charge| > Limit

Stop if the absolute value of accumulated charge is greater than the value entered in A-hr.

o|Energy| > Limit

Stop if the absolute value of transferred energy is greater than the value entered in joules (J).

 

Stop At 2

AE Channels

An optional parameter that appears only if an instrument with the Auxiliary Electrometer option is connected. If your instrument does not include the AE feature, this configuration parameter will not be visible.

 

This parameter consists of checkboxes that allow to select which channels are active during the experiment. Click the All button to select, or None to deselect all channels.

 

There is a Set Limits checkbox available for some experiments. It opens a secondary AE Channel Limits window where limits for the individual AE channels can be entered. The checkbox for each AE channel turns the limit-checking on for that channel. The Under (V) parameter tests for voltages less than the entered value. The Over (V) parameter tests for voltages above the entered value. If the measured value on an AE channel exceeds one of these limits, the experiment skips to the next step or ends if there is no next step.

 

 

Related Topics

Potentiostatic - setup page 1