Problem with set_integration_time, the spectrometer doesn't wait for spectrum acquisition.

[josue300earth]

spectrometer and system information

• model: (USB2000+)
• operating system: _(Windows 10)
• python version: _(python 3.8.8)
• python-seabreeze version: _(2.0.3)
• installed-via: (conda install)

current problem

detailed description of what doesn't work
My problem is simple I run this code:

spec.integration_time_micros(10000000) # 10 seconds
wavelengths, intensities = spec.spectrum()

however, when I establish the integration time and I acquire the spectrum, the program immediately takes a spectrum and shows it, not waiting until the spectrometer finishes the acquisition process. In a few words, the code "spec.spectrum()" doesn't block the spectrometer when it takes the spectrum. And the resulting spectrum is equal, no matter the integration time I use.
I read other similar problems, but I don't use the "trigger mode" in my application, I just want only take a simple spectrum with different integration times.

minimal code example and error (very helpful if available)

This the code :

from seabreeze.spectrometers import Spectrometer, list_devices
import matplotlib.pyplot as plt
import time

devices = list_devices()
spec = Spectrometer(devices[0])

set integration time

spec.integration_time_micros(10000000) # 10 seconds

wavelengths, intensities = spec.spectrum() #correct_dark_counts=True
plt.plot(wavelengths[10:],intensities[10:])

This code doesn't send error messages; it just doesn't work like it is supposed to.

My doubt is, does python work with the spectrometer this way? Or I do something wrong. I didn't have problems with the installation o errors.

[ap--]

Hi @josue300earth

By default the spectrometer is constantly acquiring spectra. When you switch to a long integration time, the last spectrum taken at the short default integration time is still in the buffer.

If you run the following, you'll see that it'll take a 10 second spectrum:

from seabreeze.spectrometers import Spectrometer, list_devices
import matplotlib.pyplot as plt

devices = list_devices()
spec = Spectrometer(devices[0])

# set integration time
spec.integration_time_micros(10000000) # 10 seconds
_ = spec.spectrum()  # throw away last spectrum...
wavelengths, intensities = spec.spectrum()
plt.plot(wavelengths[10:],intensities[10:])

Let me know if that fixes your issue.

Cheers,
Andreas 😃

[josue300earth]

Hi Andreas, thank you for python code ad your quick answer. Well, here is my story; I did prove the code that you sent me, and it didn't work, so I talked with other lab partners, and they lent me another spectrometer; it turns out that the spectrometer that I work has some damage because the new spectrometer works perfectly with previous code. I repeat, thank you.

Regards Joshua.

[ap--]

That's great! Happy to hear you found the cause.
I will close this issue now. Feel free to open another one in case there's anything else.

Cheers,
Andreas 😃