Time Electronics 5075 User manual

User Manual
5075
Digital Multimeter
Version 1.1
June 2021
Time Electronics Ltd
Unit 5, TON Business Park, 2-8 Morley Road,
Tonbridge, Kent, TN9 1RA, United Kingdom.
T: [phone] | F: [phone]
[e-mail] | www.timeelectronics.com

© 2021 Time Electronics Ltd.
All rights reserved.
Nothing from this manual may be multiplied, or made public in any form or manner, either
electronically or hard copy, without prior written consent from Time Electronics Ltd.
This also applies to any schematics, drawings and diagrams contained herein.
This manual provides operating and safety instructions for the Time Electronics product.
To ensure correct operation and safety, please follow the instructions in this manual.
Time Electronics reserves the right to change the contents, specifications and other
information contained in this manual without notice.

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Contents
1Safety Guidelines...........................................................................................................................5
2Introduction....................................................................................................................................6
3Installation......................................................................................................................................7
3.1 Rear Panel............................................................................................................................................. 7
3.2 Grounding Requirements ......................................................................................................................7
3.3 Power Requirements ............................................................................................................................. 8
3.4 Setting the Line Voltage ........................................................................................................................8
3.5 GPIB (IEEE 488) Connection ................................................................................................................8
3.6 Bench Use .............................................................................................................................................8
3.7 19” Rack Mounting ................................................................................................................................9
4Basic Operation Procedure ........................................................................................................10
4.1 Switching On .......................................................................................................................................10
4.2 The Display..........................................................................................................................................11
4.3 Warning Messages..............................................................................................................................12
4.4 Keys..................................................................................................................................................... 12
4.5 DC Voltage Measurements.................................................................................................................. 15
4.6 DC Current Measurements.................................................................................................................. 18
4.7 Resistance Measurements ..................................................................................................................21
4.8 Capacitance Measurements................................................................................................................ 25
4.9 Using the Diode Tester........................................................................................................................26
4.10 True RMS AC Voltage Measurements ................................................................................................27
4.11 True RMS AC Current Measurements................................................................................................. 29
4.12 Measuring AC + DC Voltage or Current ..............................................................................................30
4.13 Frequency Measurement Using AC Function......................................................................................31
5Advanced Operation Procedure .................................................................................................32
5.1 Menu Options ......................................................................................................................................32
6Measurement Techniques...........................................................................................................38
6.1 Common Mode Noise and Using the Guard Terminal......................................................................... 38
6.2 Using the Guard on Resistance...........................................................................................................39
6.3 Input Impedance and Lead Capacitance .............................................................................................40
6.4 Thermal EMF’s ....................................................................................................................................40
6.5 Making High Value Resistance Measurements ................................................................................... 42
6.6 DC Current Measurement Errors.........................................................................................................43
6.7 AC Measurements............................................................................................................................... 43
6.8 True RMS ............................................................................................................................................ 44
6.9 Bandwidth............................................................................................................................................ 44
6.10 Crest Factor.........................................................................................................................................44
6.11 Zero AC Input Error .............................................................................................................................45

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7IEEE (GPIB) Operation ................................................................................................................46
7.1 Data Transfer and Device Addressing.................................................................................................46
7.2 IEEE Cables ........................................................................................................................................46
7.3 IEC Bus Connections ..........................................................................................................................46
7.4 IEEE Connector................................................................................................................................... 47
7.5 IEEE Address Selection ...................................................................................................................... 48
7.6 Local/Remote Operation......................................................................................................................48
7.7 Interface Clear Command - IFC........................................................................................................... 48
7.8 IEEE Command Format ......................................................................................................................49
7.9 Terminating Character......................................................................................................................... 49
7.10 IEEE Command Execution ..................................................................................................................49
7.11 IEEE Command List ............................................................................................................................ 50
7.12 Transmitted Value Format ................................................................................................................... 51
7.13 Programming Example ........................................................................................................................ 52
8Re-Calibration ..............................................................................................................................53
8.1 Calibration Source ............................................................................................................................... 53
8.2 Warm Up Time ....................................................................................................................................53
8.3 Front Panel Re-calibration...................................................................................................................54
9Specifications .............................................................................................................................. 55
9.1 Technical/General Specifications ........................................................................................................55
9.2 Operating Information/Features........................................................................................................... 55
10 Scanner Option 9726 ...................................................................................................................58
10.1 Fitting the Scanner (Option 9726)........................................................................................................58
10.2 Connections......................................................................................................................................... 58
10.3 Operating the Scanner ........................................................................................................................ 59
10.4 Scanner Specifications ........................................................................................................................ 59
11 5075 Internal Componentry Information....................................................................................60
11.1 Digital Board ........................................................................................................................................60
11.2 Analogue Board................................................................................................................................... 61
11.3 True RMS AC Voltage Measurements ................................................................................................62
11.4 True RMS Current Measurement ........................................................................................................62
12 Fault Diagnosis............................................................................................................................63
12.1 Fault Check List...................................................................................................................................63
12.2 Fuse Replacement ..............................................................................................................................64
12.3 Replacement of Analog or Digital Boards............................................................................................66
12.4 Replacing the Clock Backup Battery ................................................................................................... 67
13 Spare Parts List ...........................................................................................................................68
14 Warranty and Servicing............................................................................................................... 69

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1Safety Guidelines
This manual contains information and warnings, which the operator should follow to ensure
their own safety and continued operation of the instrument.
The 5075 has been designed and tested in accordance with the recommendations of IEC
348 Class 1.
Protection is assured by a direct connection via the power cable from ground to exposed
metal parts and internal ground screens. The line connection must only be inserted in a
mains power outlet provided with a protective earth conductor and continuity of the ground
conductor must be assured between the socket and the instrument.
Always ensure that when measuring high voltages the V+ and V– input terminals are
connected correctly. (V+ connected to the most positive potential with respect to earth and
V– to the nearest potential to earth).
If any sign of malfunction or if the instrument shows visible signs of damage, the instrument
should be repaired only by a skilled engineer who is aware of the potential hazards
associated with mains operated equipment.
Maximum Voltages Between Terminals
Do not exceed these specified voltages between terminals otherwise serious damage will result.
Between V+ and V– terminals < 1100V DC
Between High Voltage and V– terminals < 10kV DC
Between V– and Guard < 200V DC
Between Guard and Earth < 500V DC
Before switching the equipment under test off, disconnect the inputs, especially when
connected to equipment capable of delivering a high voltage. (High back EMF’s can damage
the 5075).
Interruption of the protective mains earth conductor, either internal or external to the
instrument is potentially hazardous.
The terminals marked with this symbol carry the potential of the source under test.
These terminals and any other connections to the source could carry lethal high voltages
and at no time should they be touched during a high voltage test. Switch off the source
before attempting to rectify any problems associated with the test.

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2Introduction
A benchtop digital multimeter that combines high performance and accuracy with simple
operation. With speed and precision, the 5075 measures from nanovolts to 10 kV, from
picoamps to 30 Amps, from nano-ohms up to 1 GΩ, and from picofarads to 300 μF. It is ideal
for users requiring a cost-effective DMM with multiple functions and exceptional resolution
and accuracy up to 7½ digits.
This makes the 5075 is a versatile solution to essential laboratory calibration and verification,
covering a wide range of applications with excellent measurement capabilities, whilst
maintaining reliability and performance.
The Auto Dynamic Filter (ADF) mode allows the 5075 to automatically select the most
suitable filter. For a fast-changing signal or for when the signal is first connected the reading
is displayed almost immediately, but if the input remains constant, the filter time is increased
to provide a more stable accurate reading. If the input were disconnected the filter would
immediately return to the fastest.
Operation is simple, all major functions from range selection to null require just one key press.
The large 24 digit display shows clearly the range and reading and can even show the time to
the next sample if required. Other functions can be easily selected from a scrolled menu.
Functions for diode/zener tests, max/min, peak hold and continuity checks are available and
also various audible warnings can be selected. A bar graph function allows the user to
program high and low pass/fail limits and switch to the bar display mode. This will give an
audible and visual indication to the user of the components specification.
A low thermal 10-channel scanner option, allows multiple inputs to be displayed or compared
without the additional cost and inconvenience of a separate switching arrangement.
The 5075 can be controlled via Time Electronics EasyCal software to automate the
calibration process. This provides increased speed of calibration and consistency of results.

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3Installation
This chapter contains information about the power requirements, fuses and installation of the
instrument into a 19” rack mount frame.
3.1 Rear Panel
3.2 Grounding Requirements
The multimeter is supplied with a three conductor A.C. power lead. This lead must be
connected to a three-conductor power supply that has its ground conductor connected to an
electrical earth (safety ground). The power socket and cable both comply with IEC safety
standards.
For continued protection against electrical shock, always ensure that the instrument is
properly earthed.
Calibration
Key Socket
IEEE address
selection
IEEE
connector
Rear input
terminals
Capacitance
fuse
Power
Switch
Mains input and
voltage selector
Scanner Inputs
(option 9726)
Current
fuses

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3.3 Power Requirements
You can operate the multimeter from a single-phase source rated at 110 V AC, 220 V AC, or
240 V AC 50/60 Hz.
Line voltage may vary by up to 10 % but must not exceed 250 V AC.
The power lead must be wired in accordance with the diagram below.
Be sure that the voltage setting on the instrument is correct before connecting to a power
source and that the correct fuse has been installed.
3.4 Setting the Line Voltage
To alter the line voltage setting, firstly remove the power lead from the instrument.
Remove the fuse holder/voltage setting cartridge from the power connector then locate and
remove the fuse holder.
Rotate until the correct voltage setting is displayed in the window.
Install the correct fuse and replace the cartridge (800 mA for 220/240 V AC or 1.6 A for
110 V AC).
3.5 GPIB (IEEE 488) Connection
This instrument implements the requirements of the IEEE - 488/1978 standard.
The connection is made by a standard 24 pin IEEE connector mounted on the rear panel.
The IEEE address is selected by a DIP switch again on the rear of the instrument as shown
below. Refer to Chapter 7 for IEEE operations.
3.6 Bench Use
The instrument may be used free standing by using the tilt feet on the base.
The front panel terminals are permanently connected inside the instrument to the rear panel
terminals. Before making any connection to the front panel terminals, ensure that any rear
panel terminations have been removed (or vice versa).

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3.7 19” Rack Mounting
Refer to Figure 3.1, removing the feet and Figure 3.2, rear fixing detail.
To mount the instrument in a 19” rack you must first have the 19” rack mount kit (part # 9728).
First remove the two tilt feet and two standard feet from the base of the instrument and then
remove the carrying handle.
Fix the two mounting ‘ears’ on each side of the instrument using the two fixing holes and the
2BA screws.
Locate the rear support fixings as in Figure 3.2 on the rack and fix using the screws provided.
Mount the instrument in the rack, locating the two ‘ears’ in the rear support fixings.
Fix the front of the unit to the frame using the screws provided.
As before, decide which terminals are going to be used. Only one set of connections should
be made to the front or rear terminals.
Figure 3.1
Figure 3.2

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4Basic Operation Procedure
This chapter provides an introduction into the operation of the instrument. The more
advanced features and functions may be found in the next section.
Before operating the DMM ensure that the mains voltage setting is correct and that the
correct fuse has been installed.
Also check for any options that may have been installed such as the AC / frequency option
or the Scanner option.
4.1 Switching On
The mains power switch is mounted on the rear of the instrument.
When the instrument is powered up, it will run through a limited self-test routine, display the
version number of the internal software, the IEEE address, the instruments serial number,
the calibration date, next calibration due date, calibration temperature and calibration period.
This may be by-passed by pressing the Key at turn on.
The multimeter will default to DC volts and auto-range. The display then shows the
measured voltage and the mode of operation. The LED’s above the keys will also show
which mode of operation has been selected.
The initial state at power on is:
•Function DCV
•Range Auto
•Resolution6 1/2 digits
•Filter 500ms
•Auto Dynamic Filter On
•Dual Display Off
The 5075 will perform an internal calibration of the full scale, zero and linearity of its A/D
converter every 5 minutes or when the internal temperature changes by more than one
degree Celsius. This will take less than 1 second.
During this time the display will show:
+ 0 . 00000 mV IntCal