Close Focus Lens

The Close Focus (CF) lens for compact pyrometers allows precise measurement of small objects in short distances, with the minimum spot size depending on the sensing version. It has specific transmission values for minimal signal loss. CF lenses come in internal or external thread types for direct installation to the sensor heads or integration into the massive housing or air purge. It is compatible with LT, 1M, 2M, 3M, and 4M models.

General Specification

• Size: Ø14 x 11 mm ( Ø12 x 5 mm with external thread)
• Operating temperature: -20 °C to 200°C
• Storage temperature: 0 °C to 70°C
• Thread size: M12
• Housing Material: Stainless steel

Materials / Combinations

• Germanium – for LT
• Silicon – for 4M
• Borosilicate – for 1M, 2M, 3M

Typical Transmission

• LT: 0.78
• 1M: 0.80
• 2M: 0.87
• 3M: 0.92
• 4M: 0.93

The shown values are typical and may vary between different delivery batches.

What is the focal point with the additional Close-Focus lens?

The focal point differs depending on the sensor’s distance-to-spot ratio and wavelength. Please review the corresponding datasheet of the sensor version or use the optics calculator.

What is the minimum spot size when using the Close Focus lens?

The minimum spot size depends on the used sensing head. The distance is always measured from the front edge of the CF lens holder or laminar air purge collar.

How do I install the Close Focus lens?

Turn the CF lens until it reaches the end stop to install it on the sensing head. To combine it with the massive housing, please use the version with external thread M12x1.

What wrench size is required to screw on the CF Optic?

The wrench size is 14mm.

• 1x CF-lens