Device for monitoring and/or measuring parameters of a running, thread-like or wire-like test material and method for operating the device

Device for monitoring parameters of a running, thread-like or wire-like elongated test material, comprising:

• means for establishing a measuring gap which provides for passage of the test material, said measuring gap having two side walls each of which is provided with a measuring electrode forming part of a capacitive measuring element for monitoring the cross-section of the test material;
• and,
• means for optically measuring the test material within said measuring gap, said optical measuring means including an optical measuring element for monitoring the diameter of the test material, said optical measurement element further including a light source arranged on a side of the measuring gap and a photoelectric element positioned to receive light from said light source, the capacitive measuring element and the optical measuring element being formed as part of a common measuring head.