Gemstone Refractometer FGR-003

Gem refractometer /Gem tools Gemological (Gemstone) Refractometer with Built-in Light Source+ Refractometer Index oil

  Gemstone Refractometer /Gem tools

Features

1.Hard CZ measuring prism.2.Scale range:1.35-1.85.Accuracy: less than  ±0.0033.Professional optical design, Aluminum alloy table and Internally installed the monochromatic light.4.There are two ways of inputing the voltage:7AA batteries and DC3V direct current suply(AC100—240V).5.2ml refringent oil(1.78±0.005) with unique design of the bottle(Proprietary technology ZL200620096730.7),6.It is much safer ,much ecnomical and more convinent.

  SpecificationsRefractometer size:140mm*90mm*40mm/5.51in*3.54in*1.57insuitcase size:210mm*190mm*96mm/8.27in*7.48in*3.78inWeight: 0.86kg/1.86lb what included:

 1.Refractometer

2.Polaris filter3.AA battery x24.AC100-240V power suppy5.refractive index Liquid(1.78±0.005)with unique designed bottle6.Refractometer Index Reference List (up to 200 common gemstones, i.e. Calcite, Jadeite, Quartz etc.)7.User's ManualFactory offer 1 year full warranty and life time limited warranty 

Operating Information:

Open the upper cover then wash the gem and prism with alcohol.Lay the instrument on the worktable. Drop a little bit of special refractive oil onto the surface of prism and press it by a thin glass bar. (Be sure not too much or too little) Make sure the ground surface of gem to be measured is close to the prism, press it again lightly, let the refractive oil be evenly distributed between the two surfaces then close the upper cover. Press the light momentary switch, make sure that the internal light source is turned on when testing. Move the eyepiece up and down and adjust the diopter accordingly. By this time you can see a light/dark boundary in the viewing field. The gradation (shade) on which the boundary located is called the refractive index of gem.MEASURING METHODS: Remove the polarizer. Turn it onto eyepiece. Then turn the polarizer lightly. You can only read the refractive index value in one direction at a time because the polarizer only allows the light vibrated in one direction to pass through.Turn the polarizer through 90°, you can measure the refractive index value of the light vibrated at right angles to that mentioned above.Turn the gem in the same direction through small degree then turn the polarizer lightly according to above method, you can read the two refractive index values of the light vibrated at right angles to each other.Operate continuously until the gem is at 180° position to its initial position. From a number of groups of measured refractive index values you can find the maximum and minimum refractive index. The difference between the two values is the birefringence of gem.

Maintenance:

After measurement, remove any dirt from the refractometer's housing (casing) then clean the prism and the gem with alcohol to remove the refractive oil on it.Put back the refractometer into the box for protection.Remove the Battery from the Battery compartment if you are planning on not using the Refractometer for a long period of time to prevent leaks or molds that can damage your device.

Gemstone Refractometer FGR-003