Ocean Optics HG-1 Mercury Argon Calibration Source

Ocean Optics HG-1

The compact, low-cost HG-1 Mercury Argon Calibration Source is a spectral wavelength calibration source for UV-VIS-Shortwave NIR spectrophotometric systems. The HG-1 produces first order mercury and argon spectral lines from 253-922 nm and second order argon lines to 1700 nm for use in performing fast, reliable spectrometer wavelength calibrations. Easily identifiable mercury and argon spectral emission lines are printed on the HG-1 housing.

With the HG-1 and an Ocean Optics spectrometer, users can perform wavelength calibration with a spreadsheet program such as Microsoft Excel or a calculator that performs linear regressions. For technical assistance in performing the latter option, click on Calibrating the Wavelength of Your Spectrometer.

The HG-1 features an SMA 905 Connector to couple to Ocean Optics spectrometers and fiber optic accessories, including optical fibers. The HG-1 operates with a 12 VDC power supply (included with the unit) or 9V battery (not included).

User's Tip

Ocean Optics spectrometers are carefully calibrated as part of the company's standard quality assurance process. However, as is the case with all spectrometers, wavelength will drift slightly due to time and environmental conditions. If wavelength accuracy is an important part of your work, consider including calibration spectra with every experiment.



Low-pressure gas discharge lines of mercury and argon

Spectral range:

253-1700 nm

Dimensions (in mm):

125.7 x 70 x 25.8

Power consumption:

250 mA at 12 VDC

Power requirements:

12 VDC wall transformer (included) or
9 VDC battery (additional)

Internal voltage:

600 volts at 30 kHz

Bulb life:

~ 3,500 hours (at 20 mA)

Amplitude stabilization:

~1 minute


3 mm


SMA 905

User's Tip: Ocean Optics recommends using the HG-1 with a 50 µm-diameter or smaller optical fiber or entrance slit. The use of  fibers and slits >50 µm in diameter will result in optical resolution (full width, half maximum) that adversely affects wavelength calibration. Also, keep in mind that if the spectrometer has no slit and your experiment involves using optical fibers of different diameters, wavelength re-calibration will be required. That's because optical resolution will vary according to the diameter of the fiber in use -- i.e., a 50 µm fiber will resolve differently than a 100 µm fiber, and so on. Recalibration is also recommended every time that you unscrew the fiber from the SMA 905 Connector on the spectrometer.

Spectral Output

Mercury emission lines are <600 nm. Argon emission lines are >600 nm, and are shown here on an exaggerated amplitude scale.

Strong Hg Emission Lines by Wavelength (nm)

User's Tip: There are more emission lines published here than printed on the label on the HG-1 housing. The label is intended as a quick, convenient reference and does not list every Ar or Hg emission line that exists.

253.652 404.656
296.728 407.783*
302.150 435.833
313.155 546.074**
334.148 576.960
365.015 579.066

* This spectral line will not be evident with spectrometers configured with 300- or 600-lines/mm gratings.

** With spectrometers that have 1200-, 1800-, 2400- or 3600-lines/mm gratings, spectral lines will be evident at 576.96 nm and 579.07 nm.

Strong Ar Emission Lines by Wavelength (nm)

696.543 800.616*
706.722 811.531
710.748 826.452
727.294 842.465
738.398 852.144
750.387 866.794
763.511 912.297
772.376 922.450

* This spectral line will be evident only with spectrometers configured with 1800-, 2400-, or 3600-lines/mm gratings.

Cuvette Wavelength Calibration Adapter

The PS-HG1-ADP Wavelength Calibration Adapter is a 1-cm square fixture that fits into a 1-cm pathlength sample chamber and connects to the HG-1 via optical fiber. (Neither wavelength calibration standard or fiber is included). The adapter is designed for performing a wavelength calibration for any spectrometer and 1-cm cuvette holder system, whether it's designed by Ocean Optics or another manufacturer.

The PS-HG1-ADP is $300.


Wavelengths of Spectral Lines in Mercury Pencil Lamps
Applied Optics-OT, Vol. 35 Issue 1 Pages 74-77 (January 1996)
Craig J. Sansonetti, Marc L. Salit, Joseph Reader

Irradiances of Spectral Lines in Mercury Pencil Lamps
Applied Optics-OT, Vol. 35 Issue 1 Pages 78-83 (January 1996)
Craig J. Sansonetti, J.M. Bridges, Joseph Reader

Per Reader, et al, Wavelengths and Transition
Probabilities of Atoms and Atomic Ions
NSRDS-National Bureau of Standards #68, 1980

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