HL
HG Long (wavelength emission line scan)
This is a command but not a routine. It is run from the prompt or schedule (HL) and is used or executed from within the HH routine code. This command configures the instrument to scan the HL (Long wavelength) HG emission line, scanning the 334.148 nm line from 333.1nm to 335.1nm, scanning at 0.025nm increments.
The test can indicate the accuracy of the dispersion and the accuracy of the spherical mirror placement within the instrument by measuring the wavelength of the emission line against the ideal wavelength and recording the measured slit width (FHHB - Full height, Half Base of the scanned emission line image). A mirror that is mounted too close or too far from the other optics within the optical frame will increase the FHHB value in angstroms.