CLOSED ON: 24 MAY 2020  |  REWARD: INR 3,00,000
Reward money is paid in exchange of legally acquiring the solution, implementing it to solve the problem and meeting the success criteria. Milestones for paying the reward money would depend upon the complexity of challenge and maturity of the proposed solution, which would be discussed with the solver as soon as the proposed solution is selected by us.
Under Evaluation

Short Description:

We are looking for low-cost handheld devices to accurately measure the zinc coating thickness of GI wires.

Challenge Details

Galvanization or galvanizing is the process of applying a protective coating to steel or iron, to prevent rusting. The most common method of galvanization is hot-dip galvanizing, in which the parts are submerged in a bath of molten hot zinc. We have a continuous hot-dip galvanization setup for producing galvanized iron (GI) wires. The wire diameters range from 1.4 - 5 mm and corresponding zinc coating range from 50 - 300 gsm i.e. 7 to 50 microns.

It is sometimes observed that there is a variation of zinc coating across the length of wire. Currently, we undertake offline zinc coating tests (volumetric zinc coating as per IS 6745) from test samples. This is a reactive mode of determining the coating thickness and does not give continuous feedback to the operators. Any necessary corrective action is thus delayed. 

Hence, we are looking for a portable zinc coating measurement system which will quickly provide the coating thickness (online or portable offline) and help the operator to correct the process parameters, without having to cut the test samples & wait for results.

Options Tried:

  • Portable zinc coating probes are available for flat Galvanized sheet products. Similar probes are not applicable for wires
  • There are a few offline testing devices, which are very expensive and not portable (handheld). They need samples to be cut and brought to the machine.
  • Eddy current based zinc coating sensors are not suitable for thin coating lines because of limitations of accuracy (± 15 gsm).


  • If the proposed solution is for an offline system, the device needs to be portable, handy, and easy to operate, with a preference for clamp-on types.
  • The desired accuracy is ± 0.1 microns with high repeatability.

Constraints: The wire speed in the zinc coating line is up to 130 meters per minute.

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