It should be noted here that the extended mode operations (i.e. operating over the range of 43 to 197 m) is time consuming. The observer should be aware that he will get a spectrum over the nominal LWS wavelength range also by specifying a wavelength range of 45 to 170 m. The wavelength range between 170 and 180 m will then also be covered, although not at the best S/N. If the observer wants to get this range also at the best S/N, he should specify an end wavelength of 180 m. This is then observed using an extended range scan. Specifying the long wavelength extended range (longward of 170 m will cost some 40% extra time, and is therefore only advisable if the observer wants to get the best S/N at the longer wavelengths.