With Single wave length Pyrometer
How do we adapt a pyrometer into an application? The engineer's answer to the customer's request
The choice of a particular type of pyrometer is due to several reasons, the temperature range in the application, emissivity changes, and the wavelength most suitable to measure the material.
The pyrometer we will offer fits all requirements and even with slight advantages.
The customer needs an equivalent pyrometer to the competition’s pyrometer, and our recommendation is based on analyzing the competitor’s pyrometer specification and offering our best equivalent. If the customer is interested in different performance specifications, they should provide us with a detailed requirements specification and, based on that, try to offer replacement pyrometers.
We assume the customer's choice of this specification is due to the following reasons:
- Temperature range
- Emissivity changes
- And wavelength suitable for measurement
The pyrometers A250 and A250C meets some of the requirements, but not all.
Pyrometer A250, a single-wave pyrometer, cannot handle emissivity changes.
Pyrometer A250C can handle emissivity changes, but measures in different wavelengths, and its minimum temperature is higher.
An error in the measurement of one wavelength pyrometer resulting from a change in emissivity of the measured target.
An illustration based on trials of galvanized or Zn-coated surfaces, which are not fully homogenized, and the emissivity changes from point to point.
To demonstrate the measurement error we took a simple sample with three different emissivity’s: 0.1, 0.15 and 0.2. We may set only one emissivity setup for a single wavelength pyrometer- in our case, setting an average value e=0.15. Then we calculated the measurement error resulting from emissivity changes along the strip. While the actual strip temperature is TR=300C, and the pyrometer wavelength is λ=1.6mkm. If we use longer wavelengths (for measurement of lower temperature), variations will be even more significant. These are the main reasons for our offer of the A-2W pyrometer.
Several pictures from the
customer allow us to
accurately match the
pyrometer to the process.
