LDC1000 - Measuring different types of metal

Hello Jason,

Are you interested in metal identification/ Could you please describe the application in more details, and we will be glad to help.

Specifically I would like to see what data TI has for measuring different types of metal.  For example, comparing steel to stainless steel.  My understanding is that the LDC1000 is able to measure the conductivity of the metal so it should be able to determine the differences but was hoping for data related to this type of measurement. 

Thank you for your feedback,

Jason

Hello Evgeny,

I also try to differ metal materials like silver, cupper or lead by measuring the conductivity using the LDC1000.
Unfortunately my experiments with the EVM kit were not succesful up til now. In fact, the amplitude of proximity data and inductance varies testing different metal materials, but not equivlant to the conductance of the metal. For example, lead should have about one-tenth of the amplitude of cupper because of the lower conductivity, but depending on different sensor coils an sensor capacitor sometimes cupper has a lower sensor amplitude in comparsion to lead. Do you have a hint regarding the design of the sensorsystem to achieve a "conductivity meter" using the LDC 1000 ?

With best regards,

Michael

Hello Michael,

I would take Rp Measurements of known large targets at a fixed position from the coil, and plot them (Ro data) as a function of conductivity of those targets.

Then I'd have a look-up table/fit function, so I could measure unknown metals.

Hi Evgeny,

thank you for your prombt answer.

The problem is, that the there is no correlation between the conductance of the metal and the amplitude of Rp.
The eddy current increases with better conductance of the material, so the higher the conductance the higher the amplitude, isn't it ?
You mentioned, that you have experience identify metal using the LDC1000. Do I have to keep a special combination within the sensorsystem to perform the measurement ?

Best regards,

Michael

Hello Jason,

Are you trying to detect metal composition or you are interested what metal types can be used as targets? Please, feel free to give me a call to discuss.

Best Regards,
Natallia Holubeva

Hi Natallia,

I want to detect metal composition. The sensorcoil-diameter should be as small as possible for this appilcation.

Best regards,

Michael

Hello Michael,

I believe Evgeny explained above how to create a look up table.

Best Regards,
Natallia Holubeva

I didnot slove the same problem about measuring resistivity of metal with the temperature ,look up a table may be need some
standard sample .

the model that the central of the coil is hollow ,the metal at the central is right?I am looking forward that TI give me a good mehod. I have been puzzled by this for two months .

Hello Zjinfeng,

Could you please describe what particular issues you are running to?

Best Regards,
Natallia Holubeva

Hello Natallia Holubeva,
    I want to test the resisivity of procedure of the liquid metal transforming to solid metal ,the temperature is -50°C to 50°C, I want to plot the resisivity line with

Hello Zjinfeng,

Unfortunately I dont have an example for such an application. My lab does not have necessary equipment to melt the metal. I would suggest you to take sample data and create a lookup table based on it. After the table is created, you may take the measurements and compare them to your sample data. The constains such as coil, distance, temperature must remain similar to the ones you used for the lookup table.

Best Regards,
Natallia Holubeva