Mirror side detection

Task:

We want to differentiate on which side a small mirror is laying. 
The object reflects light on both sides. 
One side of a mirror is usually coated with a thin metal layer.
 

The solution: 
Our metric inductive sensor 1079292 IMC18-08BPPVC0SA00.

This device comes with IO-Link and shows the current signal level of the object under its sensing head in the sensor parameterization software SOPAS ET.


How to set up: 

1.) Mount the IMC18 around 4-5mm over the object you want to detect and connect it to SOPAS ET via IO-Link Silink box.
Exact sensor object distance, very good object guiding and stable sensor mounting is crucial.

→ downside

->upside

2.) Go online on SOPAS ET and check how the signal behaves on every side of the mirror. If the coated side is on the mirror downside, the signal is less than upside (higher digit value). If the signal level difference is too small, decrease the distance between sensor and object. 

3.) Set up two windows. One window for Qint1 (mirror downside) and one for Qint2 (mirror upside).

4.) Now enter the "logic" flag of the IMC18 in SOPAS ET. Set it up like the picture shows below. No mirror: Signal around 7800. Coated side downside: Signal around 7250. Coated side upside: Signal level 6250.

To avoid double output switching, we need to set up a T-On-delay on Qint1. Otherwise the signal would run on its way to window Qint2 through window 1 of Qint1. The time value depends on your application speed. 
    

5.) Check if everything is working just fine.