摘要 |
An adhesive dispensing device includes a heater unit for melting adhesive, a fill system communicating with a receiving space for feeding the heater unit, and a reservoir for receiving melted adhesive from the heater unit. The dispensing device also includes a capacitive level sensor located along a sidewall of the receiving space such that the level of adhesive in the receiving space can be detected by sensing the difference in dielectric capacitance where the adhesive is located compared to where air acts as the dielectric. The size of the driven electrode produces a broader sensing window capable of generating multiple control signals corresponding to different fill levels of adhesive. The receiving space and reservoir are minimized in size so that adhesive is not held at elevated temperatures long enough to char or degrade. |