As the title suggests, electronic testers are electronic. In spite of the name, some require manual processes for preparation of the test. These electronic testers work by applying testing liquid and having results read by an electronic device.
Electronic testers fall into one of three general categories.
The testers in this category are capable of distinguishing gold purities up to 18k and require manual preparation for the electronic authentication. These gold testers are generally less expensive than their category 2 counterparts because they are less sensitive.
The testers in this category are capable of distinguishing gold purities up to 24k, and, like category 1 testers, also require manual preparation for the electronic authentication. The 24k testers are much more sensitive and can distinguish between high karat alloys. Because of this, they are more prone to user error.
The testers in this category are those that are fully electronic, and do not utilize a manual component. These testers are the most expensive.
Most electronic testers are made by one of three companies, Oris Nelson Enterprises, Gemoro and Tri Electronics.
Both Tri Electronics and Gemoro offer professional instruments that can be used for testing large volumes of items on a daily basis. The Mizar tester by Tri Electronics is better suited for low-volume testing and is generally less expensive to buy (but more expensive per test due to higher testing liquid cost).
Here is an overview of popular gold testers:
Oris Nelson Enterprise
Oris Nelson offers 2 testers. One has indicator lights for three gold purities 10k, 14k and 18k+ and will cost about $150 to $250. The other has readings for 9k, 10k, 12k, 14k, 16k, 18k, 20k and 24k and will cost about $200 to $300.
Gemoro offers a tester which tests up to 24k gold as well as platinum. There are lights indicating purities including “no gold”, 10k, 14k, 18k, 24k, and platinum. This unit will cost about $250 to $300.
Tri Electronics makes several lines of testers.
Their microprocessor based line is pretty cool because it displays the gold purity in both karats and percentages on a digital display, but you’ll pay a more for it. They also may a similar line which require you to use a conversion table to look up the purity based on the number it displays. Each line has a product that tests gold up to 18k and 24k. These units will cost between $250 and $750.
They also make portable testers, which are great if you are buying gold at places such as garage sales and antique shops. These testers test white gold up to 18k and yellow gold up to 24k and will cost you around $300 to $400. Additionally, they have an express tester that tests gold purity that is 10k, 14k or 18k+. This tester will cost around $150 to $250.