its size and weight have been reduced to minimum, and all controls have been
grouped on a front panel with a roll-down protective cover.
bail-style carrying handle, a rugged Formica case, and internal foam
cushioning provide for convenient, safe hand-transportability; and optional,
fitted, fiberglass shipping container provides protection from all normal
shipping stresses on commercial carriers. When fully charged the batteries
maintain control of the chamber temperature for at least two weeks at room-
Four invertible saturated standard cells
(1.018000 50V) with porous septa. Connections accessible
at four isolated, unplated copper terminal pairs on front
EMF limit of error:
report supplied to
microvolts for each cell, referred to the legal standard of
voltage as maintained by the National Research of Canada
(NRC) and the US National Bureau of Standards (NBS).
be sent to NRC or NBS for report to lV or better.
temperature of 23C -2C.
Drift less than 0.02C for one year.
Drift less than 0.02C after exposure to 0C
or 35C for a period of 1 hour and within 0.005C when
followed by 2 hours in an ambient temperature between 20C
connects via front panel terminals
to external null
detector (not furnished).
Drift less than 0.01C per year.
Bimetallic sensor shuts down control
circuit and activates OVERTEMP indicator on the front panel
when the inner chamber temperature exceeds 35C 2C.
Front panel indicators:
AC ON lamp
Meter indication of heater cycling
Meter indication of battery state of charge
Meter indication of overtemperature