The protective window models PWS, PWL and SIWS are designed to help protect the lens of Calex infrared temperature sensors from mechanical damage, and to help
retain fragments of the lens if it is damaged. These windows may be used with sensors that have a measurement wavelength of 8 to 14 µm and an adjustable emissivity setting.

Plastic or Silicon window?

The plastic versions (PWS/PWL) are better suited to food and pharmaceutical
industries.

The silicon version (SIWS) can handle a higher ambient temperature, up to 180 °C
compared to 100 °C for the PWS, although the ambient temperature should still stay
within the sensor’s limits. However, it has a slightly lower transmissivity, around 69%
compared to 77% for the PWS.

For example, in the case of the PyroMiniBus or PyroMini, the sensors can withstand
ambient temperatures higher than 100 °C, in which case the SIWS would be the better choice. So, ultimately it depends on the client’s requirements and application.

Using the window

To use the protective windows, mount the infrared sensor as normal, ensuring at least 3.5 mm of thread for the window holder, then screw the window and its stainless-steel holder fully onto the sensor and tighten with a spanner. Because the window reduces the infrared signal, the sensor’s emissivity must be adjusted: multiply the target emissivity by the window’s transmissivity to obtain the new setting. For example, for window model PWS:

Once this value is applied in the sensor menu, temperature measurements can begin
as normal.

For sales enquiries, technical support, or more information, please call us at 01525373178 or drop us an email and we will get back to you as soon as possible.