Dear customers,

For those of you who had purchased our TN500 (AI483) and TN420 (AI482) turbidimeters, here is the product recall information that we would like to let you know:

We have found the USB power adapter in these two products has a chance to burn when being plugged with a high voltage charger together in a surge protector. 

To solve this problem, we are offering a free replacement of a new UL-certified charger to you. We encourage you not to use the old charger before receiving the new charger for safety purposes.

There is no need to ship the product back to us. Please email us at with the subject "Adapter Replacement Request", adding your name, shipping address, and proof of purchase. We will ship out the new power adapter within one business day upon receiving your email.

Sincerely we apologize for this inconvenience and we hope to help you avoid this risk as soon as possible.

Apera Instruments Customer Care