Hot Metal Detectors (HMD)Back to list ›

Scanning Hot Metal Detector
Rota-Sonde DC3000

  • Two sensitivity ranges: 750 °F and 480 °F
  • Remote control of the sensitivity
  • Self-monitoring


  • Easy alignment of the sensor.
  • Assured detection regardless of the transverse position of the product.
  • Precise detection thanks to the narrow lateral field.
  • Reliable detection because of the small analyzing beam.
  • Photosensitive cell that best suits application in rolling mills, despite scale and steam.
  • Very low maintenance.


The Rota-Sonde DC3000 is a scanning hot metal detector for continuous caster and rolling mill applications, offering two sensitivity ranges and two self-monitoring functions.
The "high sensitivity" range enables detection of steel product at a temperature as low as 480 °F.
In this way, the Rota-Sonde DC3000 is convenient for all hot metal detection applications in the Steel Industry and its self-monitoring facility optimizes preventive maintenance.

Examples of applications

The Rota-Sonde DC3000 is perfectly suitable for all detection applications of low-temperature rolled product or low emissivity materials such as hafnium.
It is also convenient for applications where a change in the process or material leads to major variations in the temperature of the product or its emissivity, as after quenching, or for special steels, etc...

If the apparent temperature of the material is uncertain during the design stage, the choice of the sensitivity range of the Rota-Sonde DC3000 can be selected during commissioning.


The Rota-Sonde DC3000 is a scanning sensor, which is sensitive to the infrared radiation emitted by hot products.
It is a self-contained detector including:

  • An optoelectronic case with an air purged protective hood.
  • A cooling plate with an adjustable mounting stand.

Because of its design, particularly its cast aluminum case, the Rota-Sonde DC3000 is specially adapted for the harsh environment of the Steel Industry (impacts, vibrations, heat, vapor and dust).

Operating principle

1. Scanning system

The detection field is scanned by a rotating polygonal mirror which reflects the infrared radiation from the product to the photocell.
Because of the exclusive optical scanning principle, the Rota-Sonde DC3000 offers the following advantages:

  • Easy alignment and reliable detection, regardless of the transverse position of the product, thanks to the large vertical field angle.
  • Accurate detection because of the narrow lateral field.
  • Reliable detection due to the small analyzing beam.

All these features give accurate and reliable detection, whatever the dimensions and the temperature of the product, or its distance and its position in the scanned field.

Photosensitive cell

The Rota-Sonde DC3000 is fitted with a special photosensitive cell, suitable for detection of hot product, even at a temperature as low as 480 °F.



The Rota-Sonde DC3000 is enclosed in a sealed cast aluminum case.
A hood for protecting the window glass is fitted with an air-jet facility to blow a vertical air curtain in front of the glass; the protective hood can be hinged down to clean the window.
The case is mounted on a cooling plate including a stainless steel pipe and fixed to a mounting stand, adjustable in two axes.
The water and air purging connections are on the support plate, this way it is possible to remove the sensor without first disconnecting the water and air supplies and without need of optical re-alignment.



  • Sensitive photocell with an optimal spectral sensitivity to detect product at low temperatures and in the presence of
  • Two sensitivity ranges with remote selection.
  • Case mounting connector and mating connector fitted with high temperature cable.
  • Plug-in circuit.
  • Control panel behind a hinged cover and including:
  • - a direct sighting through the detector itself for easy alignment.
  • - two sensitivity setting potentiometers (one for each range).
  • - a TEST button to control a built-in lamp which simulates the presence of product
    in the field.
  • - a three-color LED :
    Green: product absent
    Red: product present
    Orange: cell signal saturated
    Off: alarm

Self monitoring functions

In order to optimize preventive maintenance and to improve reliability, the Rota-Sonde DC3000 offers self monitoring functions including:

  • Monitoring of the excessive internal temperature (limit of 131 °F) indicating a fault in the cooling system.
  • Monitoring of the cell signal variation to indicate dirt on the window or incorrect sensitivity setting.
  • Alarm indicating a power supply or scanning defect.

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