BAIRD &. TATLOCK (LONDON) LTD. 



5574-5583 



Callendar's Recording Pyrometer. 



This instrument is based on the Wheatstone's bridge principle, but instead of the bridge having to be balanced 

 by hand adjustments, it is done automatically by the recorder itself. The contact which slides to and fro on the 

 bridge wire BW carries a pen which writes on a drum. The movement of the pen is controlled by two clocks 

 which in turn are controlled by electro-magnets. The galvanometer pointer carries two insulated wires which 

 can make contact on one side or the other of a platinum tipped contact wheel. When the pen is indicating the 

 correct temperature these contacts do not touch the-wheel, but if the temperature changes one or other of the 

 contacts is made causing one electro-magnet to release its clock and draw the pen carriage along the bridge wire 

 until the balanced condition is again restored. A 4-volt accumulator is necessary to operate the recorder. 



5574 r Price, adjusted for one particular range of temperature. Drum rotating once in 25 hours 



also 2 hours 5 minutes. Including 100 standard charts . . . . . . . . 37 15 



5575 T Ditto, but with Wayne's Continuous Paper Movement to give a record extending over one 



week . . . . . . . . . . . . . . . . . . 41 



5576 T Zero Coil, to enable the zero of the above recorders to be raised (e.g. a coil may be supplied 



to alter the range 01000 F. to 7001800 F.) . . . . . . . . . . 0156 



5577 r Gallendar Recorder with range across scale 100 or 200 C. Fitted with switchboard to 

 enable the zero value to be made any temperature desired in steps of 50 C. Drum 

 rotating in 25 hours or 2 hours 5 minutes .. .. .. .. .. .. 40 10 



5578 T Ditto, but with drum rotating once in 12 hours or once in i hour . . . . . . 40 10 



5579 T Ditto, but with Wayne's Continuous Paper Movement to give a record extending over one 



week . . . . . . . . . . . . 43 10 



Dust-tight cupboard for recorder. Fitted with glass door . . . . . . . . 2 18 



Spare 25-hour Charts. Almost any range . . . . . . . . . . per 100 050 



Spare 7-day Charts for recorders 1071 and iogt . . . . . . . . per 25 050 



11 



5580 T 

 5581* 

 5582* 

 5583 T 



Repair Outfit for any of the above recorders, including soldering iron, solder, phosphor-bronze 

 strip, and fine silver wire, also camel's-hair brush . . 



14 CROSS STREET HATTOTST GARDETST, E-C 



1002 



