MNL-1009 REV A
18
5.
Disconnect the QE
Pro
from your computer.
6.
Re-plug the spectrometer into your computer.
The system should now be able to locate and install the correct drivers for the USB device.
Apple Mac OSX Operating Systems
Since there are no device files for the QE
Pro
Spectrometer in a Mac operating system, you should not encounter any problems if you
installed the spectrometer before the operating software.
Linux Operating Systems
For Linux operating systems, all you need to do is install the software, then unplug and re-plug in the spectrometer. Technically, the
driver files for Linux simply give nonprivileged users permission to use newly connected hardware.
There isn’t any long
-term harm to
plugging in the device before installing the software.
FPGA Firmware Upgrade
The FPGA firmware in the QE
Pro
should be upgraded using the USB bus. Upgrading the FPGA firmware in the QE
Pro
via the RS-232
serial bus produces unpredictable results.
TEC Readback Accuracy at Temperature Extremes
The TEC temperature is read back by a thermistor embedded in the detector. As with most thermistors, the relationship between
resistance and temperature is non-linear. However, the QE
Pro
uses a piecewise linear interpolation to convert from resistance to
temperature. This linearization is targeted at the range from -20
°
C to 40
°
C. Accuracy will deteriorate beyond the edges of this range.
TEC Readback Temperature Not Exactly at Setpoint
The settled TEC readback temperature is slightly different from the TEC setpoint temperature, typically by ~0.2 °C. However, on other
Ocean Insight products (and some competitive products), the TEC temperature appears to settle exactly at the TEC setpoint
(generally when the TEC control loop uses a common ADC for both control and readback). The QE
Pro
uses an ADC that is
independent of the control loop, resulting in a more reliable value. Although TEC accuracy is typically not very important to users, TEC
stability (outstanding on the QE
Pro
) is critical.
