Model 77480 MS127i 1/8 m Spectrograph with various slits
The MS127i is a versatile, efficient, single grating, imaging spectrograph at an affordable price. For spectroscopy applications not covering a broad spectral range, and not requiring the resolution and imaging performance of our high end MS260iTM and MS257TM ¼ m instruments, the MS127iTM is the right choice. For a specification comparison of all our spectrographs, refer to Table 1.
The MS127i has been designed for ultra low stray light and no re-diffracted light. It utilizes a Czerny-Turner optical layout with one significant modification - the addition of an astigmatism correcting mirror after the collimating mirror (see Fig. 1). This patented system allows high spectral and spatial resolution at a low F/#, F/3.8.
Wavelength setting is manual on the MS127i. The instrument is calibrated for the central wavelength of the image field when using a 1200 l/mm grating. If you are working with a 2400, 600, 400, etc. l/mm grating, multiply the wavelength setting by the wavelength scale conversion factor listed in Table 2. Although the simple drive mechanism does not allow very accurate wavelength settings, it is highly reproducible and will allow you to switch between pre-determined wavelength positions with confidence.
Full correction for astigmatism in spectral instruments requires sophisticated toroidal mirrors (as in our MS257 1/4 m spectrograph); they allow vertical resolution of many tracks simultaneously. But, for many applications there is a need for only 2 to 3 tracks, as in double beam work. We designed the MS127i to correct astigmatism economically. You can reliably separate multiple tracks for Multi-track Spectroscopy with a CCD that has the ability to record individual tracks, such as our InstaSpec CCDs. Thus, MS127i makes the acquisition of double beam spectra of pulsed or continuous sources possible on a limited budget.
A normally closed shutter located behind the input slit effectively blocks light from entering MS127i. The shutter circuitry is housed inside MS127i; shutter power is from a simple 5 V supply, provided. Minimum opening time is 0.2 s. This shutter will operate at rates to 0.5 Hz.
We offer a large selection of interchangeable gratings for the MS127i. Choose the one that covers the spectral range of interest. The gratings are supported on a precision holder, which clips into the grating mount. They can be easily interchanged without the need to realign the instrument. Table 2 lists the specifications for each model.
MS127i comes with an input slit holder. We provide fixed slits in widths from 10 to 200 µm.
MS127i has 1/4-20 tapped holes for rod mounting, or you can simply sit it on a flat surface. It is heavy enough to support a detector, without being hard mounted to a baseplate.