Time Electronics 1024 DC Current Calibrator - Manual (Page 3)

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1024 Technical Manual 3
1. Introduction
1.1. Description
• Up to 100mA output
• 0.02% accuracy
• 10 ppm/hr stability
• Null facility
• Portable
• Battery & mains operation
The 1024 is a solid state battery powered instrument which is easily portable and convenient
for laboratory, field, or industrial use. It incorporates many of the well-proven circuit
techniques of the Time Electronics Type 1010 DC Voltage Calibrator.
The null balance system enables the 1024 to be used for making accurate current
measurement in addition to its basic function as a calibrator. Operation is by backing the
current source output against the current to be measured, with the difference being
displayed on a sensitive centre zone null meter. At the null point, there is no voltage drop
across the 1024.
The 1024 employs a precision aged reference diode as a basic reference source. Excellent
zero stability is ensured by the use of a high performance FET chopper amplifier system.
Precision metal film resistors with temperature co-efficients of less than 10 ppm per ºC are
used to maintain the accuracy and stability of the initial calibration.
Operation is from battery or mains. A front panel indicator that also serves as a supply on-off
display monitors the battery supply condition. A minimum line on the indicator shows when
the batteries should be recharged. Charging is performed by its own internal charger/power
supply. Simply plugging the 1024 into a mains supply will charge the batteries. Operation of
the 1024 may be continued when plugged into the mains.
Applications include calibration and testing of current sensitive transducers; calibration and
linearity tests on digital and electronic current meters; and semiconductor parameter
measurements e.g. diode conduction voltages at specified current levels.