Optical detectors "BQ" of moving yarns
1.Application 
BQ sensors are designed to detect presence of ayarn at draw-twist machines. They can be advantageously used evenon other types of machines and appliances where ballooning or traversing yarns.The moving yarn is monitored by an infra red beam. There is no contact with theyarn and clearances are such that anybuilt up of dirt, fly, and spin finish on the detector are minimal. Reliabledetection is possible for a wide range of neutral or synthetic yarns as well asblends and filaments such as nylon, glass and carbon fibre. Sensitivity is notaffected by colour, material, spin finish or conductivity.
2.Description
BQ sensor is a compact unit containing scanningelements, amplifier, signal evaluation, and output switch circuit. The systemresponds to signals produced by the yarn motion. A compensation circuitcorrects for even extreme build up of dirt and fly, to ensure 100% accurate andreliable detection of breaks.
A part of the sensor is a connection cableended according to a customer's requests. In the sensor's body, there are twoholes for fastening the sensor and two control lamp diodes. The red controllamp diode HL1 (on the left side when looking from the operating area) signalsthe absence of the oscillating motion inoperating area. The control lamp diodeHL2 on the right, serves to signal states of superior appliance according toneeds of user.