Antique 'Wedge Optical Pyrometer' Cochrane's, Furnace / metal / glass / ceramic Temperature gauge

Marked 'The Wedge Optical Pyrometer', 182/3 Temple Chambers, London, E.C,

No449, Cochrane's Patent'

Dated around 1910

Rare item, I cannot find a similar example currently for sale !

The optical pyrometer is used in many industrial applications to measure non contact high temperature measurements. The optical sensor red scales can Calibration Equipment, Ceramics, Furnaces, Metals and Alloys, Non Contact Thermometers, Optical Pyrometers, PetroChemical, Power Generation

A pyrometer is a type of remote-sensing thermometer used to measure the temperature of distant objects. Various forms of pyrometers have historically existed. In the modern usage, it is a device that from a distance determines the temperature of a surface from the amount of the thermal radiation it emits, a process known as pyrometry and sometimes radiometry.

The following link maybe of interest.https://collection.sciencemuseumgroup.org.uk/objects/co8611997/wedge-optical-pyrometer-pyrometer

Please note that the above Science Museum example, has a serial number of 549 and is dated 1900 - 1920. My example is 449, so presumably an earlier example. 

700 - 1600c temperature scale

Appears in working order. Some slight wear, marks, scratches and tarnishing. The internal red glass lens is not cracked. Plus, there may have originally been a tube which extends out from the body, towards the heat sauce, which is now missing.