A few months back we discussed how important it is to check chemical compatibility before you purchase your sensor. This time we would like to highlight an application where finding chemical compatibility is especially challenging.
What Doesn’t Work
We have some customers that monitor the levels of HCl (hydrochloric acid). At this time, only two of our sensors are capable of doing this. This is due to the corrosive nature of HCl. As you may already know, hydrochloric acid will devour metals like stainless steel and titanium. But you may not know that in addition, HCl will also have a severe effect on common plastic materials like polyurethane, polycarbonate, and PVC. Due to the picky, or rather hungry, characteristic of the acid, most contact sensors are not a good solution for the application. For this reason we recommend our non-contact ultrasonic sensors.
Most of our ultrasonic sensors have a Kynar® (PVDF) transducer face. On the Cole-Parmer database, Kynar® has a chemical compatibility rating of “A” when it is coupled with HCl. This means that the HCl should have no damaging effect on the material.
But wait, we are not done yet. While the transducer faces are made of Kynar®, the mounting threads are typically polycarbonate. If the acid were to come into contact with this material, the sensor would be damaged. For this reason, we recommend that you consider our ultrasonic sensors that have both a transducer face and mounting threads constructed of Kynar®. This way the sensor’s housing is completely protected. The two models we have that meet this criteria are our LPU-2127 and the LOE remote monitoring sensor.
If you have any questions about this application, or if you have experience with overcoming chemical compatibility challenges, please give us a call.
Kynar® is a registered trademark of Arkema Inc.