PicoampControl

PicoampControl was created to control the KEITHLEY picoampere meter 6482.

Installation

This library uses pyvisa. You need to install NI-VISA, follow https://pyvisa.readthedocs.io/en/latest/introduction/getting.html#backend

To install the library use pip:

pip install git+https://github.com/martinunland/picoamp_control.git

Usage

First, import the PicoampControl class, create a PicoampControl object and connect to the picoamperemeters:

from picoamp_control import PicoampControl
picoamp = PicoampControl()
picoamp.connect() 

connect() will try to find the picoamp device. If it fails, you will have to pass the com port, e.g.:

picoamp.connect(com='COM3')  # Replace 'COM3' with the appropriate port for your device

After connecting, you can configure the instrument using various methods. auto_config should be enough for almost all uses

picoamp.auto_config(plc=10) #plc is number of power cycles that are integrated for a reading, 1plc = 20ms in a 50Hz utility frequency (EU)

You can configure the measurement range manually, passing a valide range with the enum CurrentRanges, but I recommend always using the autorange (applied in auto_config)...

from picoamp_control import CurrentRanges
picoamp.set_channel_range(range_ch1: CurrentRanges.rng_2_mA, range_ch2: CurrentRanges.rng_20_nA)

Finally, you can use the get_mean_current() method to retrieve the mean and standard error of the mean for a specified number of current readings:

(mean_ch1, error_ch1), (mean_ch2, error_ch2) = picoamp.get_mean_current(n=10)

If you are measuring from two channels, with one of the channels being a reference of the other (i.e. you need the ratio between both channels), then you may use the method "get_mean_ratio_background_substracted()". This is more accurate than calculating the ratio from get_mean_current, since now you consider small variations in time.

ratio, ratio_err, mean_ch1, mean_ch2 = picoamp.get_mean_ratio_background_substracted(n=10, background_ch1, background_ch2)