Teledyne 311 - Portable trace oxygen analyzer - Manual (Page 5)

flashlight. The life of the cell is warranted by TAI (see Section 4.4) in a fashion similar to that
employed by the manufacturers of automobile batteries. This procedure guarantees the customer
compensation for failure of a given cell to perform as specified.
1.3.2 Reliable Calibration. The unique qualities of the Micro-Fuel Cell allows
the user to calibrate the instrument with the most economical, reliable, abundant, standardization
gas there is -- atmospheric air.
The special “CAL” range of the instrument features a mark that coincides with the 209,000 ppm
oxygen concentration of air. By drawing air through the instrument (see the Sample Calibration
Procedure in Section 3.2) reliable calibration can be achieved.
After the electronics have been properly zeroed (a one-time factory operation), the instrument
cannot produce an output indication in the absence of oxygen; therefore, the need for a “zero”
standardization gas is obviated (Refer to Section 5 if readjustment is required).
1.3.3 Integral Power Supply. The differential power requirement (plus a
minus 3.6 volts D.C.) of the instrument amplifier is furnished by two internally mounted 750
milliampere hour nickel cadmium batteries. Fully charged, these batteries will provide enough
power to operate the instrument continuously for a period of about thirty-five (35) days.
Furthermore, an overnight charge on a one-month duty cycle should keep the original batteries
supplied usable for many years.
An integral charging circuit and a detectable power cord are provided so that the batteries may be
recharged from any 50 or 60 cycle, 105 to 125 volt, convenience outlet.
The instrument is designed to either sample or have its batteries recharged. Both operations
cannot be carried out simultaneously. TAI has deliberately interlocked the circuitry so that both
operations cannot be carried on at the same time.
Only when the selector switch is placed in the OFF position will the neon lamp on the back plate
of the Model 311 light up to indicate power to the battery charging circuit.
* U.S. Pat. Nos. 3,767,552 and 3,668,101
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