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Ratio and Multi-Wavelength Williamson Pyrometers offer a single-wavelength (SWL) mode of operation.The following notes pertain to commonly asked questions associated with this function. SWL mode can be used to compare readings to single-wavelength models and as a troubleshooting tool.

Is the SWL reading available simultaneously with the TC, DW or MW reading?

Yes, for the Williamson products the single-wavelength reading may be obtained simultaneously with the TC, DW or MW reading. This is different from the approach offered by competitive units. For competitive units, only one mode of operation is available at a time.

When the SWL mode is enabled, does the pyrometer reading change?

Yes and No. The value displayed on the pyrometer display, and the value provided by the analog output does not automatically change when the SWL mode of operation is enabled, but rather, the SWL reading becomes an available parameter to be displayed or to be selected as an output signal. To change the pyrometer display, the user must scroll through the list of available parameters to select the SWL reading.

How is the SWL parameter viewed or accessed as an analog output signal?

IM Main Display: Press and Hold the Enter button to scroll through available parameters.

IM Lower Display: Use the arrow keys to scroll through the available parameters.

Pyrometer Human Interface: Use the arrow keys to scroll through the available parameters.

Analog Output Signal: Use the Configure I/O submenu group to select the SWL parameter.

Alarm: Use the Configure Alarm submenu group to select the SWL parameter.

Is the SWL value available as a digital output signal?

Yes, the SWL signal is included as a digital output signal. When the Single-Wavelength Mode is enabled, the SWL value appears as the 10th (unfiltered value) and 11th (filtered value) in the continuous data stream. When using bi-directional communications, the command for the unfiltered SWL temperature value is US and the command for the filtered SWL temperature value is FS. When the SWL mode is disabled, these commands result in a blank response and the value in the data stream is a blank.

Do older Williamson pyrometers include the SWL feature?

No. SWL (Single Wavelength) Energy, Unfiltered Temperature, and Filtered Temperature parameters are available in Dual- and Multi-wavelength sensors using software code 2.0.5837 (July 2009 release) and later, with IM firmware 2.0.2914 and later, and only when the Single-Wavelength operating mode is Enabled in the Configure ESP Submenu. When not Enabled or when using an earlier sensor software version, the command is considered invalid and the returned response is blank as described below.

What Signal Conditioning is applied to the SWL Reading?

The filtered SWL reading has an emissivity adjustment and a time average applied to it, but no other signal conditioning is applied. The peak hold and ESP filtering features do not apply to the SWL output signal.

How is the emissivity set for SWL mode?

The SWL emissivity value is set in the Configure ESP submenu group. This parameter is displayed only when the SWL feature is enabled.

Can the analog input value be used to adjust the emissivity setting?

No, the analog input value may not be used to set the emissivity for the single-wavelength mode for these types of pyrometers. The analog input value may only be used to set the e-slope offset or the alarm 1 setpoint value.

Which wavelength is used to determine the SWL temperature value?

The longest wavelength is always used for the SWL mode of operation.

How Do I know which temperature value is displayed on the IM display?

When the SWL value is displayed on the IM main display, the unit (F or C) symbol flashes alternately with three horizontal lines. This is done to inform the user that the value is the SWL value rather than the TC, DW or MW value. When the SWL value is displayed on the pyrometer human interface or on the IM lower display, then the value is described as the SWL value in text.

Is the SWL feature compatible with ProView software?

Yes. When the SWL feature is enabled in the pyrometer, then the SWL value (both filtered and unfiltered) is recorded and may be viewed using ProView data acquisition software.

For more information about the unique features and functionality of Williamson Pyrometers please click the link below.

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