Does a labeling machine necessarily require a transparent label sensor?

Nowadays, machinery is widely adopted in production, so labeling machines can be seen everywhere, which help improve work efficiency. Correct operation guidelines are extremely important, and we should keep this in mind. Some customers have questions regarding label sensors. After purchasing a labeling machine for applying transparent bottle labels (7μm), they noticed that the supplier’s quotation included an additional "transparent label sensor". Why is there an extra charge for installing this imported component? Is a label sensor a mandatory part for labeling machines? If transparent labels are used, is a dedicated transparent label sensor absolutely required?
Anyone with a basic understanding of the working principle of automatic labeling machines knows that a label sensor is an essential component. It detects whether the label is conveyed in place, allowing the machine to send out the labeling signal. There are many types of label sensors: some for transparent labels, some for non-transparent labels, and others compatible with both. Standard labeling machines from manufacturers are normally equipped with sensors for common non-transparent labels. Customers applying transparent labels need to select an optional "transparent label sensor". If both transparent and non-transparent labels are to be used, a universal sensor supporting both types can be adopted, eliminating the need to install two separate sensors. If only non-transparent adhesive labels are applied, a transparent label sensor is not required as an optional extra!