Testers & scales calibrated before despatch

Gem & precious metal testers, since 1986

Digital refractometer by Presidium (model Prim II)
Digital refractometer by Presidium (model Prim II)
Digital refractometer by Presidium (model Prim II)
Digital refractometer by Presidium (model Prim II)
  • Load image into Gallery viewer, Digital refractometer by Presidium (model Prim II)
  • Load image into Gallery viewer, Digital refractometer by Presidium (model Prim II)
  • Load image into Gallery viewer, Digital refractometer by Presidium (model Prim II)
  • Load image into Gallery viewer, Digital refractometer by Presidium (model Prim II)

Digital refractometer by Presidium (model Prim II)

Vendor

Ref: REFRACT-DIGI-PRESID

Regular price
£279.00
Sale price
£279.00
Regular price
Unit price
per 
inclusive of VAT. Shipping calculated at checkout.

Buying in bulk or need help? Email us today

Pickup available from Quicktest (WD18 8PH)
Email us or call on 01923-220206 for appointment.

SUMMARY

We are a UK company offering fast delivery and easy telephone support

Made by Presidium, the leading manufacturers of gem testing equipment.

There is downloadable software to connect it to your computer. The reading is then displayed along with a list of stones that match the reading, and you can click on each stone to see more information (constants). This saves time looking up charts.

Comes with a USB cable (connects to a computer); USB-mains plug; laminated card with list of refractive index numbers for common gemstones.

Works with loose stones and also stones mounted in small items of jewellery.

USES:

- to confirm stones are as described by your supplier

- to show a customer the reading, when you already know what the stone is and just need to 'prove' it

- to sort parcels of stones to see which look 'interesting' and worthy of further investigation, and then...

...to narrow the possibilities down to a handful of stones (sometimes just 1 or 2 stones!) so that you can carry out further investigations.

 

PROS AND CONS

Advantages, as an electronic tester:- instant reading and no waiting time between tests

- tiny sensor for testing stones down to 3mm diameter

- stones can be loose or can be mounted in small items of jewellery

- pull-out refractive index chart as a quick-reference for diamond / diamond simulants (including Moissanite) and

- pocket-size Refractive Index Chart with R.I. readings for 55 stones

- built-in 8-piece gemstone holder (sets of sample gems are an optional extra)

- battery-operated plus USB port for alternative power source and (if required) to connect it to a computer

- use the downloadable software [from Presidium], each test will display data on the computer listing many variables (in addition to refractive index) that will help you identify the stone.

Disadvantages, as an electronic tester:- although mounted stones can be tested, the item of jewellery must be placed over the sensor so that the top (table) of the stone covers the hole, and this is not possible with large or 'lumpy' items of jewellery

- the surface of the stone must be perfectly flat, perfectly polished and perfectly clean (i.e. most stones but not cabochons and beads)

- it is a sensitive piece of laboratory equipment, it must be kept clean and dry, the sensor must be kept dust-free, it must not be bumped in and out of bags or used on damp outside market stalls

- as with all testers, there are many stones with the same, or similar, readings

Advantages over an optical refractometer:- gives higher readings (1.00 to 3.00) and this enables it to test for diamond and for simulants such as Moissanite

- no contact fluid required

- fast and easy to use, easy-to-read digital display

Disadvantages over an optical refractometer:- it's not as versatile as an optical refractometer, you only get one reading for each stone (technical: you can't measure the birefringence).

- this Presidium "Digital refractometer" does measure refractive index but, technically, it is not a refractometer, it is a reflectivity meter that uses a clever computer program to calculate refractive index. You probably don't need to know that!  All you need to know is (if you are familiar with the optical refractometer) it does not show double refraction and so, for the expert, is not as flexible as an optical refractometer. 

SPECIFICATIONS

Range of measurement, 1.000 to 3.000

Power: one 9 Volt battery + USB

Size 5 X 3 X 2 inches (125X 75 X 50mm)

Item weight 150g. 

INFO + ACCESSORIES

Have you seen the Fascinating article about gem testers? This will answer many questions about electronic gem testers (all electronic gem testers!) - how 'reliable' are they? How 'easy to use' are they?

In summary: no gem tester will light up with a number (or name) that tells you, with 100% certainty, the name of the gemstone. This is because nature does not make gemstones to a standard formulae, there are always variations. All of gemmology is a detective game, starting with an idea of what the gemstone might be (that is what electronic gem testers are for) then using knowledge and skill to find the answer.

Disclaimer

All equipment and materials must be used in conjunction with the user's skill, knowledge and experience. Under no circumstances shall QUICKTEST be liable for direct or indirect loss sustained in connection with any item. It is your responsibility to regularly check equipment against known samples, to ensure that it is working correctly.