Time Electronics 1024DC User Manual

Time Electronics

1024 DC Current Calibrator

With Null Measuring Facility

Technical Manual

V1.1 20/04/09 Time Electronics Ltd

Botany Industrial Estate, Tonbridge, Kent, TN9 1RH

Tel: [phone] Fax: [phone]

Email: [e-mail]

Web Site: www.TimeElectronic s .com

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C ontents

1. Introduction ............................................................................................................ 3

1.1. General Description ................................................................................................ 3

1.2. Specifications ......................................................................................................... 4

2. Operation ................................................................................................................ 5

2.1. Front Panel Controls .............................................................................................. 5

2.2. Operating Procedures and Precautions ................................................................ 7

2.2.1. Normal Operation ......................................................................................................... 7

2.2.2. Overload conditions ...................................................................................................... 7

2.3. Output Noise ........................................................................................................... 7

2.4. Mains Power Unit .................................................................................................... 9

2.4.1. Type PU2 ...................................................................................................................... 9

2.4.2. Constructional details PU2 ........................................................................................... 9

2.4.3. 240V to 110V conversion ............................................................................................. 9

3. Constructional Layout Details ............................................................................ 10

3.1. Chopper amplifier module ....................................................................................10

3.1.1. Description .................................................................................................................. 10

3.1.2. Module replacement ................................................................................................... 10

4. Recalibration ........................................................................................................ 11

4.1. Repairs ...................................................................................................................11

4.2. Recalibration ..........................................................................................................11

4.2.1. Calibration Procedure ................................................................................................. 12

4.2.2. Linearity ...................................................................................................................... 12

5. Guarantee & Servicing ......................................................................................... 13

All Time Electronics' instruments are subject to continuous development and improvement and in
consequence may incorporate minor detail changes from the information contained herein.

1024 Technical Manual

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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.

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1.2. Specifications

Output: 0-100mA in 5 ranges

0-99.999mA in 1uA steps
0-9.9999mA in 100uA steps
0-999.99uA in 10nA steps
0-99.999uA in 1nA steps
0-9.9999uA in 0.1nA steps

Accuracy: +/- 0.02% of setting , + /- 0.005% of range, +/- 0.2nA

Voltage Capability: 15V with new batteries or mains power

(11V with minimum allowable battery level)

Regulation: Load: Better than 5ppm per Volt
Supply: Better than 5ppm per Volt

Output polarity: Positive or negative switch selected. A centre off position
provides an open circuit on the output terminals

Out of limit warning: A front panel indicator provides a warning of insufficient
drive voltage

Output stability: Less than 30 ppm per °C (0°C to + 50°C)
Less than 10 ppm per hour at constant temperature
Less than 75 ppm per 6 months

Output noise: 100, 10 and 1mA ranges: less than 5ppm of full scale
100 and 10uA ranges: less than 10 ppm of full scale +/- 0.1nA

Null sensitivity: Adjustable from +/- 25 mA to +/- 25uA FSD via front panel
control. Maximum resolution is 0.5uA.

Power supply: Time Electronics power unit type PU2 which is housed in the
rear of the 1024. The PU2 will power the 1024 direct from the
mains or an internal rechargeable battery. The battery is
automatically charged when mains power is connected.

Dimensions: L 220mm x H 160mm x D 200mm

Weight: 3.3 Kg

1024 Technical Manual

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