Detecting infrared radiation at wavelengths between 2.0 and 2.4 µm, the PyroUSB 2.2 non-contact temperature sensors from Calex Electronics is designed specifically for measuring low-temperature targets from 45ºC to 300ºC. The short-wavelength method of measurement allows much greater accuracy, and improved tolerance of optical obstructions or errors in emissivity setting, than longer wavelength sensors. Connecting directly to a PC via a USB cable (included), the sensors operate without the need for any additional hardware interface or power supply. In addition to the USB interface, they are equipped with a selectable 0 to 20 mA or 4 to 20 mA output, which is linear with temperature. This output can be connected at the same time as the USB interface or independently. Models are available with temperature ranges of 45 to 300ºC, 250 to 1000ºC or 450 to 2000ºC. If a smaller range is required, this can be set using the included CalexSoft software, which is simple to install and requires no specialist knowledge to set up and use. It displays temperature in numerical format and on a simulated scrolling chart. Users can set the temperature range and emissivity, compensate for reflected energy, apply filtering to fluctuating temperatures and use peak or valley-hold processing to measure hot or cold objects on conveyors. The software may also be used to record measurements at any interval from 1 s to 1 week and preprogrammed to start and finish at any time or date. Audible and visual alarms can be set to warn users that the temperature is either too high or too low. The built-in OPC Server interface allows communication between the sensor and any other equipment with OPC Client capabilities, making systems integration simple and affordable. The sensor itself is 106 mm long by 18 mm diameter and made of stainless steel, sealed to IP65. It is held in place by a mounting nut (included). Fixed and adjustable brackets are offered to simplify mounting and a laser-sighting tool is available to assist in the sighting of the sensor. The high-quality lenses produce very well-defined optical paths. There are four optics to choose from. Medium and high-temperature models are available with 25:1 or 75:1 distance-to-spot size ratios, or close-focus optics, which focus on a 7.5 mm diameter spot at 500 mm distance. Low temperature models are available with a distance-to-spot size ratio of 15:1. If the sensor is required to operate in a very high or low ambient temperature (< 0°C or > 70°C) it can be ordered with a water/air-cooled jacket built around it. The temperature inside the sensor can also be monitored from the PC to make sure it doesn’t exceed the ambient limits. For dusty environments, an air-purge collar can be fitted to keep the lens clean. The sensors are RoHS compliant and conform to EN 61326-1:2006 for EMC.
Edited by: Teoman Tugsuz
