Thurlby Thandar Instruments LCR400 User Manual [en, de, fr, it]
INSTRUCTION MANUAL
LCR400
Precision LCR Bridge
Table of Contents
Introduction 2
Specification 3
EMC 6
Safety 7
Installation 8
Connections 9
Operation 10
Measurement Principles 12
Component Sorting 16
Remote Operation 20
Remote Commands 21
Maintenance 24
Instructions en Francais 25
Bedienungsanleitung auf Deutsch 45
Istruzioni in Italiano 65
Instrucciones en Español 85
1
Introduction
The LCR 400 Precision Bridge provides a fast, convenient and accurate means of measuring the
inductance, capacitance, resistance, D and Q of components with a basic accuracy of 0.1%. The
major and minor parameters of the component are displayed simultaneously.
The microprocessor controlled unit provides fully automatic mode and range selection for a wide
range of components. Control is by front panel keyboard or by RS232 link to a PC which can be
used to set up all measurement functions.
The LCR400 can be programmed to sort a range of components into bins according to value.
Multiple bins can be set to sort different tolerances of the same value or different values.
Up to nine measurement set-ups can be stored in the instrument in non-volatile memory and
called up for re-use with a few keystrokes.
Connections to the components are made via the built in four–terminal test fixture or plug–in axial
adaptor providing true contact resistance free measurements for low impedance components.
The capacitance (up to 100pf) introduced by an external test fixture can be cancelled out
permitting high impedance measurements to be made with confidence.
2
Specification
Specifications apply for 18ºC − 28ºC ambient after 30 minute warm-up.
Functions
Parameters Measured: R, L, C, D & Q.
Measurement Modes: Series or parallel equivalent circuit.
Measurement Functions: Fully autoranging including selection between L, C and R. The Zero C
function nulls out up to 100pF of stray capacitance in the test fixture.
Measurement Frequency: User selectable to be 100Hz, 1kHz or 10kHz; frequency accuracy
± 0.01%. 120Hz instead of 100Hz by factory option for 60Hz operation.
Measurement Ranges
and Resolution:
R
L
C
D
Q
Measurement Accuracy:
R (Q<0·1) 0.1% ± 1 digit
0.5% ± 1 digit
2% ± 1 digit
L (Q>10) 0.1% ± 1 digit
0.5% ± 1 digit
2% ± 1 digit
C (D<0.1) 0.1% ± 1 digit
0.5% ± 1 digit
2% ± 1 digit
Parameter
100/120Hz 1kHz 10kHz
2Ω − 1MΩ
0.4Ω − 5MΩ
0.1Ω − 20MΩ
4mH – 500H
800µH – 2500H
200µH − 9900H
10nF − 1000µF
2nF − 5000µF
500pF − 20000µF
Range
0.1mΩ − 990MΩ
0.001µH − 9900H
0.001pF − 99000µF
0.001 − 999
0.001 − 999
2Ω − 500kΩ
0.4Ω − 2MΩ
0.1Ω − 10MΩ
400µH − 50H
80µH – 250H
20µH − 1000H
1nF − 100µF
200pF − 500µF
50pF − 2000µF
2Ω − 50kΩ
0.4Ω − 200kΩ
0.1Ω – 500kΩ
40µH − 5H
8µH – 25H
2µH − 100H
100pF − 10µF
20pF − 50µF
5pF − 200µF
Q & D 0.25% ± 1 digit
Capacitance accuracies apply after null.
Measurement Update Rate: 2.5 readings per second.
0.25 − 4.0
for C = 40nF – 100µF
or L = 10mH – 50H
0.25 − 4.0
for C = 10nF – 10µF
or L = 1mH – 2.5H
0.25 − 4.0
for C = 1nF – 1µF
or L = 100µH – 250mH
Limits Comparator (Sort Mode)
Type: Comparison with multiple limits set up from the keyboard or PC via RS232 interface.
Binning: Up to 8 Pass bins for the major parameter, plus minor parameter Fail and general Fail bins.
3
Display
Display Type: Dual 5-digit 0·56” LEDs with range and function indication.
Maximum display count 50,000.
Display Functions: Simultaneous display of R + Q, L + Q, C + D, or C + R in normal
measurement modes.
Prompts to change frequency or mode to improve accuracy.
Simultaneous display of Pass/Fail status with Bin No. in Sort mode.
Inputs
Component Connection: 4-terminal connection for both radial and axial devices.
Maximum Voltage on
Component:
Bias Voltage: Switchable 2V polarising voltage for measuring electrolytic capacitors.
Input Protection: The instrument has been designed to withstand direct connection of
0·3Vrms.
capacitors charged up to 50V DC with up to 1 Joule ( ½ CV
energy.
2
) of stored
Interfaces
RS232: Serial link to PC permitting range/function control, limits setting and
results data-logging on the PC.
General
Keyboard: Full numeric keyboard for entry of limits data.
Non-Volatile Memory: Up to 9 complete set ups stored in non-volatile memory.
Power: 220V-240V AC or 110V-120V AC ±10%, 50/60Hz, adjustable internally;
25VA max. Installation Category II.
Operating Range: +5ºC to 40ºC, 20-80% RH.
Storage Range: –40ºC to 70ºC.
Environmental: Indoor use at altitudes up to 2000m, Pollution Degree 2.
Safety: Complies with EN61010-1.
EMC: Complies with EN61326.
Size: 365 x 240 x 95 mm, including feet.
Weight: 2.9 kg.
Options: Remote 4–terminal measurement interface.
4–terminal surface mount tweezers.
Kelvin Clip set.
PC logging software.
4
EC Declaration of Conformity
We Thurlby Thandar Instruments Ltd
Glebe Road
Huntingdon
Cambridgeshire PE29 7DR
England
declare that the
meets the intent of the EMC Directive 2004/108/EC and the Low Voltage Directive 2006/95/EC.
Compliance was demonstrated by conformance to the following specifications which have been
listed in the Official Journal of the European Communities.
LCR400 LCR Bridge
EMC
Emissions: a) EN61326-1 (2006) Radiated, Class B
b) EN61326-1 (2006) Conducted, Class B
c) EN61326-1 (2006) Harmonics, referring to EN61000-3-2 (2006)
Immunity: EN61326-1 (2006) Immunity Table 1, referring to:
a) EN61000-4-2 (1995) Electrostatic Discharge
b) EN61000-4-3 (2006) Electromagnetic Field
c) EN61000-4-11 (2004) Voltage Interrupt
d) EN61000-4-4 (2004) Fast Transient
e) EN61000-4-5 (2006) Surge
f) EN61000-4-6 (2007) Conducted RF
Performance levels achieved are detailed in the user manual.
Safety
EN61010-1 Installation Category II, Pollution Degree 2.
CHRIS WILDING
TECHNICAL DIRECTOR
1 May 2009
5
This instrument has been designed to meet the requirements of the EMC Directive 2004/108/EC.
Compliance was demonstrated by meeting the test limits of the following standards:
Emissions
EN61326-1 (2006) EMC product standard for Electrical Equipment for Measurement, Control and
Laboratory Use. Test limits used were:
a) Radiated: Class B
b) Conducted: Class B
c) Harmonics: EN61000-3-2 (2006) Class A; the instrument is Class A by product category.
Immunity
EN61326-1 (2006) EMC product standard for Electrical Equipment for Measurement, Control and
Laboratory Use.
Test methods, limits and performance achieved are shown below (requirement shown in
brackets):
a) EN61000-4-2 (1995) Electrostatic Discharge : 4kV air, 4kV contact, Performance A (B).
EMC
b) EN61000-4-3 (2006) Electromagnetic Field:
3V/m, 80% AM at 1kHz, 80MHz – 1GHz: Performance B
Performance B
†
c) EN61000-4-11 (2004) Voltage Interrupt: ½ cycle and 1 cycle, 0%: Performance A (B);
d) EN61000-4-4 (2004) Fast Transient, 1kV peak (AC line), 0·5kV peak (signal connections),
e) EN61000-4-5 (2006) Surge, 0·5kV (line to line), 1kV (line to ground), Performance A (B).
f) EN61000-4-6 (2007) Conducted RF, 3V, 80% AM at 1kHz (AC line only), Performance A (A).
According to EN61326-1 the definitions of performance criteria are:
Performance criterion A: ‘During test normal performance within the specification limits.’
Performance criterion B: ‘During test, temporary degradation, or loss of function or
performance which is self-recovering’.
Performance criterion C: ‘During test, temporary degradation, or loss of function or
performance which requires operator intervention or system reset occurs.’
The LCR400 is a sensitive measuring instrument and may show minor deviations in
measurement readings if subjected to RF fields greater than 1V/m and a modulation
frequency exactly that selected for the LCR400 measurement. Under all other conditions
the instrument will operate within specification (Performance A).
25 cycles, 70% and 250 cycles, 0%: Performance B (C).
Performance A (B).
†
(A); 1V/m, 2.0GHz to 2.7GHz: Performance A (A).
†
(A) and 1.4GHz to 2GHz:
Cautions
To ensure continued compliance with the EMC directive observe the following precautions:
a) after opening the case for any reason ensure that all signal and ground connections are
b) In the event of part replacement becoming necessary, only use components of an identical
6
remade correctly and that case screws are correctly refitted and tightened.
type, see the Service Manual.
Safety
This instrument is Safety Class I according to IEC classification and has been designed to meet
the requirements of EN61010−1 (Safety Requirements for Electrical Equipment for Measurement,
Control and Laboratory Use). It is an Installation Category II instrument intended for operation
from a normal single phase supply.
This instrument has been tested in accordance with EN61010−1 and has been supplied in a safe
condition. This instruction manual contains some information and warnings which have to be
followed by the user to ensure safe operation and to retain the instrument in a safe condition.
This instrument has been designed for indoor use in a Pollution Degree 2 environment in the
temperature range 5°C to 40°C, 20% −80% RH (non−condensing). It may occasionally be
subjected to temperatures between +5° and −10°C without degradation of its safety. Do not
operate while condensation is present.
Use of this instrument in a manner not specified by these instructions may impair the safety
protection provided. Do not operate the instrument outside its rated supply voltages or
environmental range.
WARNING! THIS INSTRUMENT MUST BE EARTHED
Any interruption of the mains earth conductor inside or outside the instrument will make the
instrument dangerous. Intentional interruption is prohibited. The protective action must not be
negated by the use of an extension cord without a protective conductor.
When the instrument is connected to its supply, terminals may be live and opening the covers or
removal of parts (except those to which access can be gained by hand) is likely to expose live
parts. The apparatus shall be disconnected from all voltage sources before it is opened for any
adjustment, replacement, maintenance or repair.
Any adjustment, maintenance and repair of the opened instrument under voltage shall be avoided
as far as possible and, if inevitable, shall be carried out only by a skilled person who is aware of
the hazard involved.
If the instrument is clearly defective, has been subject to mechanical damage, excessive moisture
or chemical corrosion the safety protection may be impaired and the apparatus should be
withdrawn from use and returned for checking and repair.
Make sure that only fuses with the required rated current and of the specified type are used for
replacement. The use of makeshift fuses and the short−circuiting of fuse holders is prohibited.
Do not wet the instrument when cleaning it.
The following symbols are used on the instrument and in this manual:−
Caution −refer to the accompanying documentation,
incorrect operation may damage the instrument.
alternating current.
7
Mains Operating Voltage
The operating voltage of the instrument is shown on the rear panel. Should it be necessary to
change the operating voltage from 230V to 115V or vice-versa, proceed as follows:
1. Disconnect the instrument from all voltage sources.
2. Remove the 6 screws which hold the case upper to the chassis and lift off, noting the flat
cable connector positions.
3. Remove the 4 screws securing the power supply pcb to the chassis and lift the pcb free.
4. Change the appropriate zero-ohm links beside the transformer on the pcb:
Link LK4 only for 230V operation
Link LK3 and LK5 only for 115V operation
Note that, if the change of operating voltage is accompanied by a change of supply
frequency, optimum common mode rejection of the mains will be achieved by setting the
internal 100/120Hz selection to 100Hz for 50Hz supply and 120Hz for a 60Hz supply.
This is set by the status of link LK2 which is situated immediately below the oscillator
module on the main circuit board. With no shorting link fitted to the pins the frequency is
set to 100Hz; if a shorting link is fitted it is set to 120Hz. The factory setting for 230V
operation is 100Hz and for 115V operation is 120Hz. If LK2 is changed from the factory
setting the unit will need to be recalibrated at the new frequency setting (calibration
settings for 100Hz and 120Hz cannot be held simultaneously).
Installation
5. Refit the pcb to the chassis, ensuring all connections (especially safety earth) are remade
6. To comply with safety standard requirements the operating voltage marked on the rear
7. Change the fuse to suit the new operating voltage, see below.
Fuse
The correct time-lag fuse must be fitted for the selected operating voltage.
For 230V operation use 125mA (T) 250V HBC.
For 115V operation use 250mA (T) 250V HBC.
Make sure that only fuses with the required rated current and of the specified type are used for
replacement. The use of makeshift fuses and the short-circuiting of fuse holders are prohibited.
Mains Lead
When a three core mains lead with bare ends is provided it should be connected as follows:
Brown - Mains live
Blue - Mains Neutral
Green/Yellow - Earth
as before, and refit the case upper.
panel must be changed to clearly show the new voltage setting.
8
WARNING! THIS INSTRUMENT MUST BE EARTHED
Any interruption of the mains earth conductor inside or outside the instrument will make the
instrument dangerous. Intentional interruption is prohibited.
Component Connections
The leads of the Device Under Test (DUT) are inserted in the Kelvin connectors on the top of the
instrument. Axial components can be inserted into the adaptors supplied, which themselves are
inserted into the Kelvin connectors. Both forms of connection provide true four–terminal contact
to the DUT to ensure accurate measurement of low impedance components.
The leads of radial components can be pushed directly into the spring–loaded connectors.
Alternatively, for delicate leads, the connectors can be opened by pressing down on the
connector actuators.
Similarly, the axial adaptors can be inserted by pushing directly into the main connectors; adjust
the position of the adaptors to suit the lead and body length of the axial DUT.
Ensure the contact surfaces of the Kelvin connectors are free from contamination. If in doubt,
refer to the Maintenance section.
Surface Mount Components
Plug the interface module of the optional surface mount tweezers into the Kelvin connectors.
True four–terminal connection is maintained at the tweezers.
Connections
Remote Connections
A remote test jig can be connected via the BNC connectors on the optional interface module
which inserts into the Kelvin connectors on the top of the instrument. The connectors are labelled
High Drive, High Sense, Low Sense and Low Drive. The screens of the Drive coax cables should
be connected together at the remote end and connected to the screen and case of the external
jig. The screens of the Sense leads should be isolated both from each other and from the jig
screen.
Whilst leads of up to 1 metre are unlikely to present problems, the leads to an external jig should
be kept as short as possible and the accuracy of measurements checked at all test frequencies
and over the range of values being measured before being relied upon.
RS232
9–pin D–connector for PC remote control with the following connections:
Pin Name Description
1 DCD Linked to pins 4 and 6
2 TXD Transmitted data from instrument
3 RXD Received data to instrument
4 DTR Linked to pins 1 and 6
5 GND Signal ground
6 DSR Linked to pins 1 and 4
7 RTS Linked to pin 8
8 CTS Linked to pin 7
9 – No internal connection
Connect to a PC with a cable which has pins 2, 3 and 5 wired plus pins 1, 4 & 6 and pins 7 & 8
linked at the PC end. Alternatively, since the links are made within the instrument, a fully–wired 1–
to–1 cable may be used.
9
This section covers general use of the instrument. Although the basic capabilities are largely
obvious from the keypad functions, users requiring full performance and accuracy are advised to
read this and the Measurement Principles sections in full.
Switching On
Switch on the instrument using the ON/OFF switch on the rear panel.
At switch on the instrument runs a short internal self test procedure, displays the software
version, and then waits in Auto mode for a component to measure. If it is switched on with a
component connected it will automatically detect and measure that component.
To fully disconnect from the AC supply unplug the mains cord from the back of the instrument or
switch off at the AC supply outlet; make sure that the means of disconnection is readily
accessible. Disconnect from the AC supply when not in use.
Display
Operation
10
In normal use the left–hand 5–digit display shows the value of the major parameter (L, C or R)
and the right–hand display shows the value of the minor parameter (Q, D or R). The parameters
being displayed are indicated above their respective numeric values and the units of the
parameter are shown to the right of the value itself. A display test which lights all the indicators
can be carried out by holding down any key while the instrument is switched on.
Basic measurement accuracy is 0.1% and, for the impedance range for which this accuracy is
guaranteed (see Specification) the instrument will autorange to give typically between 5,000 and
50,000 counts of display resolution. If the measured value is outside the range within which 0.1%
accuracy is guaranteed (at the measurement frequency selected) the units indicator (kΩ, pF, etc.)
will flash to show this. If the frequency indicator is also flashing, changing the frequency range
may bring the component being measured within the range of the instruments 0.1% accuracy
specification. For example, measuring 680pF at the default Auto frequency of 1kHz will cause
both the units indicator (pF) and frequency range lamp to flash; changing the frequency to 10kHz
brings 680pF within the instrument’s 0.1% specification and both lamps will stop flashing.
During the set–up and use of the sort facility the displays have other uses; these are fully
explained in the Component Sorting section.
Measurement Keys and Indicators
Frequency
Pressing the Freq key sets the test frequency for the measurement to 100/120Hz, 1kHz or
10kHz.
Note: For a 50Hz supply the lowest test frequency will generally be 100Hz, for a 60Hz supply it
will generally be 120Hz, see Installation section.
Pressing the key changes the frequency from 100/120Hz to 1kHz to 10kHz and back to
100/120Hz. The lamp indicates the setting being used. If the lamp flashes it is a warning that
another frequency may give a more accurate measurement for a component of that type and
value.
Mode
Selects either series or parallel mode equivalent circuit values to be displayed, see Measurement
Principles section. If the lamp flashes it is a warning that the other mode is the more usual
selection for a component of that type and value. If Auto mode has been selected the Mode
cannot be changed without first selecting L, C or R mode.
Bias
This applies 2 Volts DC across the test terminals to polarise electrolytic capacitors according to
the polarity marked on the Kelvin connectors. Note that applying bias to resistors or inductors
may cause a measurement error because of internal overload. Bias voltages up to 50V DC can
be applied externally, see the External Bias section of the Measurement Principles chapter.
Zero C
When measuring capacitors, pressing this button prior to inserting the component under test
zeroes the capacitance reading thereby eliminating the capacitance of the test jig. Up to 100pF of
stray capacitance may be zeroed out in this way. The correction factor is lost when the bridge is
turned off. Zero C can only be used when capacitance is being measured; if any other function is
selected the display will show
not C for 2 seconds and the command will be ignored.
R+Q, L+Q, C+D, C+R
Sets the instrument to show the major parameter in the left–hand display and the corresponding
minor parameter on the right.
Auto
In Auto mode the instrument automatically detects whether the component being measured is a
resistor, capacitor or inductor and sets the instrument to display the parameters of the test
component automatically. Note that ‘imperfect’ components, e.g. inductors with a high series
resistance, may be incorrectly detected in Auto mode and will need to have the correct function
set manually. In Auto mode the measurement frequency can be changed (by pressing the Freq
key) but the Series/Parallel mode selection is held at the default selection for that component
type, see Measurement Principles section. To change from series to parallel mode, or
vice–versa, it is first necessary to exit Auto mode by selecting the appropriate function
(R+Q, L+Q, etc.); the mode can then be changed with the Mode key.
Range Hold
Holds the measurement range at that in use when the button is pressed. This disables the auto–
ranging and minimises the settling time between measurements of similar value components.
Note that DUT voltage and current measurement are individually auto–ranged for optimum
accuracy and resolution; the processor then determines the measurement uncertainty and sets
an appropriate display resolution. Range Hold fixes all of these ranges. If a component with a
significantly different value is measured, causing any of these ranges to be exceeded, the display
will show
or (out of range) and Range Hold will need to be turned off to get a true reading.
Sorting Keys and Store/Recall Keys
The keys used to set up sorting and binning, and to store and recall complete sorting set–ups,
are described in the Component Sorting section.
11
RsZ
ω
ω
ω
ω
=
Circuit models
Resistors, capacitors and inductors can all be represented at a given frequency by a simple
series or parallel equivalent circuit. It must be stressed that this is a simple equivalent circuit and
as such will only be representative over a limited frequency range. The effects of a wide
frequency range are discussed later.
The Models used by the LCR400 are as follows:
Measurement Principles
s
Zp
+=
ω
=
+
Rp
Q
Lp
ω
2
Q
=
Ls
1+
Q
Lsj
ω
LpjRp
Ls
LpRpj
==
Rs
Rs
Lp
2
L
s
= LpQRp
Q
(D is also known as tanδ)
CpDCs )1(
Zp
jRsZs
−=
Rp
RpCpj
ω
+=1
RsCsD
ω
2
+= Rp
1
Cs
ω
1
==
RpCp
ω
=
Rs
1+
D
D
=
2
2
D
1
Q
Resistors
All resistors have parasitic impedances, both inductance and capacitance and distributed effects
of both. Fortunately, however, in normal use these parasitic effects are usually very small
compared with the resistance.
The LCR 400 provides the opportunity to evaluate the series and parallel components of resistors
at 100Hz and 1kHz and 10kHz.
Some types of resistor have more prominent parasitic effects than others. Wire wound resistors,
unless they are specially wound, have more inductance than their carbon and metal film
equivalents. Even carbon film resistors have inductance due to the inductance of the leads and
the spiral cut used to trim the resistance. There is also always capacitance between the end cap
connections - on metal film resistors it is typically around 0.25pF. This usually only becomes
significant on high value resistors or/and at high frequencies. Bifilar wound resistors may have
low inductance but the close proximity of the windings can introduce significant capacitance –
distributed along the resistance. To predict the performance of such a component at high
12
where
ω =
2πf
frequencies requires a more complex equivalent circuit than the simple two component series or
parallel circuits discussed here. In practice the solution is to select component types to match the
frequency range of the application.
For the majority of resistors, where inductive and capacitive parasitics are minimal, both series
and parallel circuits will give identical results for resistance.
For resistors where inductance is the significant parasitic, the series equivalent circuit will give the
value which matches the manufacturer’s data-sheet. For high value devices, capacitance can
start to be significant and the parallel equivalent circuit may be more appropriate.
Normally R+Q should be selected for resistors; the Q of a resistor will usually be very low –
especially at the low measurement frequencies used. However if the series and parallel
resistances at 10kHz differ significantly to those at 100Hz or 1kHz, the Q will be significant. Either
the inductance or capacitance of the resistor is producing an effect. Selecting either C+R or L+Q
will quantify the parasitic capacitance or inductance.
Low value resistors can be measured at any of the three LCR400 test frequencies but high value
resistors (>100kΩ) are best measured on the 100Hz range. The instrument warns if a
measurement is outside its maximum accuracy range by flashing the units annunciator; if
accuracy can be improved by changing the measurement frequency the frequency annunciator
will also flash, see Display section.
Capacitors
All capacitors have parasitic inductance and resistance in addition to their intended capacitance.
The leads of a capacitor can add significant inductance at high frequencies. Spiral wound metal
film capacitors can have significant parasitic inductance, which is why they are not used for
decoupling high frequencies. Some types of ceramic capacitors can provide excellent decoupling, i.e. have high capacitance with low series resistance and inductance, but can be very
lossy. Large value electrolytic capacitors can have significant inductance – this inductance can
even resonate with the capacitance at the measurement frequencies of the LCR400. This has the
effect of showing a known high value capacitor to have either negative capacitance or inductance.
Capacitors have two main types of parasitic resistance. Firstly there is the physical resistance of
the dielectric and dielectric losses; this is normally specified in terms of the Dissipation Factor ‘D’
or loss tangent and is frequency dependent. Secondly, there is the physical resistance of the
leads and the connections to the electrodes on the dielectric. The lead and connection resistance
are usually negligible, but on high value electrolytics, used to smooth power supplies, it can be
very important. The series resistance of such devices is often a manufacturers specified
parameter.
For most capacitors, other than high value electrolytics, the parallel equivalent circuit will give the
capacitance that matches the manufacturers data sheet. For low loss capacitors the series and
parallel equivalent capacitances will be the same.
Electrolytic capacitors are polarity sensitive and should be connected to the instrument correctly
and bias applied. For very high value electrolytics, for which the manufacturer specifies
Equivalent Series Resistance (ESR) the series equivalent circuit should be used.
The LCR 400 provides the means to investigate the losses of capacitors either in terms of
dissipation factor (C+D) or in terms of equivalent series or parallel resistance (C+R).
To get maximum resolution and accuracy, low values of capacitance, (<4nF) are best measured
on the LCR 400 at 10kHz after zeroing the capacitance with no component connected. Higher
values, (>10µF) should be measured at 100Hz. The instrument warns if a measurement is
outside its maximum accuracy range by flashing the units annunciator; if accuracy can be
improved by changing the measurement frequency the frequency annunciator will also flash, see
Display section.
13
External Bias
The 2 Volt DC bias available internally (see the Measurement Keys and Indicators section) is
usually adequate for polarizing electrolytic capacitors. However, it is possible to externally
connect a fully floating power supply (or battery) to give a bias voltage of up to 50 Volts DC.
The external DC bias must be connected to the LCR400 and DUT as shown in the diagram. The
High Drive, High Sense, Low Drive and Low Sense connections to the LCR400 are made using
the optional interface module which inserts into the Kelvin connectors on the top of the
instrument.
The BNC connectors on the interface module are marked with the signal names. Connect to the
power supply and DUT using screened cables, e.g. miniature coaxial cable, but leave the screens
unconnected at the remote end.
CAUTION. Always observe the correct polarity when connecting capacitors; failure to do so
may result in damage to the DUT and possible user injury.
Always discharge capacitors after making measurements with a DC bias, especially at high bias
voltages; failure to do so may result in possible user injury and damage to the LCR400 if the
charged capacitor is subsequently connected directly to the Kelvin connectors. The LCR400
has been designed to withstand the direct connection of capacitors charged up to 50V DC with
up to 1 Joule of stored energy ( ½ CV
such capacitors. Higher voltage or higher energy may result in damage to the instrument.
Inductors
All inductors have resistive losses, parasitic capacitance and an external coupled magnetic field.
The resistive losses are the resistance equivalent to losses in the core and the resistance of the
conductive wire making up the turns of the inductor. There is capacitance between each turn of
conductor and every other turn. The magnetic field of an inductor can extend outside the physical
package of the component.
2
); it should not, however, be used to routinely discharge
14
In its simplest form the resistance can be represented as a resistor in series with the inductance,
and the capacitance as a capacitor in parallel. The effect of an inductor’s self capacitance and
inductance at any given frequency combine to produce net inductance below the resonant
frequency or capacitance above the resonant frequency.
On high value inductors, such as transformers designed to work at 50/60Hz, the self resonant
frequency can be below the higher test frequencies of the LCR 400. Above the self-resonant
frequency these inductors will appear as a lossy capacitor. Due to the distributed nature of these
parasitics, the equivalent values of the resistance and capacitance change with frequency.
The leaked magnetic field, whilst usually negligible in the case of torroids, laminated core
inductors and pot core inductors, can be significant with axial inductors like RF chokes and ferrite
rod antennae. This means that the inductance of a device with a ‘leaky’ magnetic field can vary
considerably depending upon the characteristics of any conducting or magnetic material close to
the device. Any conductive material within the device’s field will contain induced currents that can
in turn have the effect of reducing the apparent inductance of the component. Conversely any
ferro-magnetic material in the immediate area of the component can have the effect of increasing
the apparent inductance. In extreme cases the inductance of a component can appear to vary
depending upon its distance above the connectors and steel case of the LCR400.
Low value inductors (<100uH) are best measured at 10kHz whilst high values >25H should be
measured at 100Hz. The instrument warns if a measurement is outside its maximum accuracy
range by flashing the units annunciator; if accuracy can be improved by changing the
measurement frequency the frequency annunciator will also flash, see Display section.
Series / Parallel connection
The LCR400 provides the capability of measuring the series or parallel equivalent circuit
parameters of resistors, capacitors and inductors.
In Auto mode the bridge uses the following models.
Resistor Series
Inductor Series
Capacitor <1µF
Capacitor >1µF
These will provide the parameters that will match data sheet values for most components.
Parallel
Series
15
The LCR 400 provides comprehensive facilities for sorting components into ‘bins’ according to
value. The parameters for each bin can be defined from the keyboard or from a PC via the RS232
interface. Binning parameters are stored with the instrument set–up; up to 9 complete set–ups
can be stored.
Bin limits are set up as percentages around nominal values and can be overlapping or sequential
(with the same nominal) or can be percentages around quite different nominals; the bins must,
however, apply to the same parameter (R, L or C).
If only one bin is set up, all components outside the range are fails. Up to 8 bins (0–7) can be
used to sort on the basis of the major parameter; bin 8 can be used to set limits for the minor
parameter only (D, Q or R) and bin 9 is the general fail bin.
Sorting Keys
The following keys are associated with sorting; they are described more fully in the sections that
follow.
Sort
Turns the sorting function on and off.
Bin No.
Component Sorting
Used for setting each of up to eight bin values.
Nominal
Used to set the nominal value for a bin and the limit for minor parameter (bin 8).
Limit
Used to set the limits for a bin, in percentages.
Numeric keys 0-9, • and ±
Used to enter the bin numbers, program store numbers, nominal values and percentage limits.
Ω µH pF
Used when entering nominal component values to set the appropriate multiplier.
kΩ mH nF
Used when entering nominal component values to set the appropriate multiplier.
MΩ H µF
Used when entering nominal component values to set the appropriate multiplier.
Enter
Used to confirm a numerical entry (value, bin number or program store number).
Store/Recall Keys
The following keys are used to store and recall set–ups:
Store
Stores the complete set–up, including the set binning values, in non volatile memory.
Recall
Recalls up to nine previously stored set–ups.
16
Simple Pass / Fail Sorting
To set up simple pass/fail sorting, first select the measurement type to be made, i.e. R+Q, L+Q,
C+D or C+R. Set the measurement frequency and select series or parallel measurement as
required.
Note: Binning cannot be set with the bridge in Auto mode.
Bin Selection
Press the Bin No. key to enter set–up mode. Successive presses of the Bin No. key will step the
display through the options of
selected bin),
press of Bin No. will enter the option sequence where it was last exited; it may be necessary to
press the key several times to get to the desired option.
CLEAR ALL? (clear all bins) and End? (exit bin set–up mode). The first
binX (where X is the bin number), CLEAr? (clear the
If any previous binning information needs to be cleared select
and press Enter; the display should show the message
the right–hand display, ready for the next step. If all bins are to be cleared select
and follow a similar procedure.
For simple pass/fail sorting, bin 0 must be used. The other bins (1 to 7 inclusive) should be
‘closed’ by setting their limits to zero; alternatively, and easier, all the bins can be cleared by using
CLEAr ALL? before bin 0 is set. Bin 8 can be used to set limits for the minor parameter (Q, D,
or R); parts that fail these limits fall into bin 8. Parts that fall into neither bin 0 nor bin 8 fall into
bin 9, the general fail bin.
Press Bin No. until
the right–hand display.
Setting Nominal Value
With bin0 displayed, press the Nominal key; the left–hand display now shows six dashes and
NOM above them.
Enter the nominal value required, followed by the appropriate units key (kΩ, µF, etc.). Press
Enter to save the value; the left–hand display now shows the value entered.
To edit an entered value simply enter a new value and press Enter again.
Setting Limits
CLEAr? with the Bin No. key
CLEAr donE and then binX in
CLEAr ALL?
binX shows in the display. Press 0 to select bin 0; bin0 should show in
With bin0 displayed, press the Limit key; the left–hand display now shows six dashes and
+LIM above them. The units indicator changes to %.
Enter the upper limit of deviation from the nominal allowed for a pass component, as a
percentage, and press Enter. Note that the minimum value that can be entered is 0.1% and the
resolution is 0.1%. The left–hand display again shows the value entered. To change an entered
value simply enter a new value and press Enter again.
Press the Limit key again; the left–hand display shows six dashes but now with
them. Enter the lower limit of deviation from the nominal allowed for a pass component, as a
percentage, and press Enter. Note that for a limit below the nominal value it is necessary to
enter a minus value using the
even both be above the nominal or both below the nominal. If no –LIM limit is entered the limits
are assumed to be symmetrical about the nominal value, i.e. if the upper limit has been set to
+0.5%, the lower limit automatically defaults to –0.5%.
The lower limit (
selecting Sort will give
17
–LIM) can be set above the upper limit (+LIM) but exiting set–up mode and
Err bin0.
± key. Note also that the limits need not be symmetrical and can
–LIM above
Minor Parameter Limits
To set the minor parameter limit (Q, D or R) select bin 8; do this by using the Bin No. key until
BinX is shown, then enter 8. bin8 will now show in the left–hand side of the display.
To enter the limit press Nominal; the minor parameter indicator (Q, D or R) will show in the
right–hand side of the display and the limit value should then be entered from the keyboard.
Press Enter to confirm the limit.
Parts that fail the minor parameter limit of bin 8 will fall into bin 8 regardless of whether the major
parameter passes the bin 0 limits. Use of bin 8 is optional; it is not necessary to set a limit and if
the limit is left ‘closed’ (the default state, indicated by dashes) bin 8 will be ignored.
Fail Bin
Parts that do not fall into bin 0 or bin 8 are assigned to bin 9, the general fail bin.
Using Sort
Having set up bin 0, press Bin No. until End? is shown in the display then press Enter to exit
the set–up mode.
Press Sort to turn on the sort facility. Parts that pass the major parameter percentage limits will
be indicated by
will be indicated by
by FAIL bin9.
PASS bin0 in the display; parts that fail the minor term limits of bin 8 (if set)
FAIL bin8, parts that do not fall into either bin 0 or bin 8 will be indicated
Storing Sort Set–ups
To store a Sort set–up press the Store key; the display shows StorE?. Press a key 1 to 9
followed by Enter; after a few seconds the right–hand display shows
set–up has been stored. The binning nominal and limits are stored, together with the Function,
Frequency, Mode, etc. used for the Sort set–up.
To recall a Sort set–up press Recall, the store number (1 to 9), and Enter. The display shows
rcl donE when the set–up has been reloaded from non–volatile memory.
Note that memory 0 contains the factory default settings; these can be loaded by pressing,
Recall, 0, Enter. Memory 0 cannot be overwritten by pressing Store, 0, Enter and cannot
therefore be used to store binning information.
Multiple Bin Sorting
The LCR400 supports two different schemes for multiple bin sorting, overlap and sequential.
Overlapping (or nested) bins have one nominal value and progressively larger symmetrical limits.
Sequential bins can also have one nominal value but asymmetric limits (e.g. –5% to –2%, –2% to
+2%, +2% to 5%) or can have different nominal values, each with their own percentage limits.
As with simple pass/fail sorting, bin 8 is the failure bin for the appropriate minor parameter and
bin 9 is the general fail bin.
Multiple bin sort schemes can be quite complicated; it is therefore a good idea to write down the
binning set–up before programming is started and to save the set–up once programming is
complete.
donE to indicate that the
18
Overlap Sorting
Overlap sorting is used when components are to be sorted into bins according to their deviation
from a nominal value, for example sorting a particular resistor value into ± 0.1%, ± 0.5% and
± 1% selections.
To set up this type of binning first select the measurement type to be made, e.g. R + Q, set the
measurement frequency and select series or parallel mode as required.
Select bin 0 and set the nominal value and tightest tolerance to be selected (i.e. 0.1% in the case
of the example) using the Nominal and Limit keys exactly as described for simple pass/fail
testing. Note that, since the limits are symmetrical, it is only necessary to set
–LIM is ‘closed’ (dashes shown in the display) the lower limit is automatically –0.1%.
Next select bin 1 in a similar way to bin 0 and set its limits to the next tightest tolerance (i.e. 0.5%
for the example). In the same way as for bin 0 it is only necessary to set
–LIM will default to –0.5% if no limit is set. Also note that it is not necessary to set a nominal for
bin 1 (and any successive bins that use the same nominal); if the nominal is left ‘closed’ (dashes
shown in the display) the nominal of the next lower bin, in this case bin 0, is automatically used.
Note that if bin 0 does not have a nominal value and limits, selecting Sort will cause the display to
show the message
+LIM to 0.1%; if
+LIM to 0.5%;
Err bin0.
Set the
Set the minor term limit (Q in the case of R + Q measurements) in bin 8 if required; bin 8 is
ignored if the limit is ‘closed’ (dashes shown in the display).
Parts that fall into more than one bin are assigned to the lower numbered bin, Thus the tightest
tolerances should be assigned to the lowest bin number, as in the example.
Unused bins should be ‘closed’ (indicated by dashes) by using the clear bin function.
Parts that do not fall into the pass bins or bin 8 are assigned to bin 9, the general fail bin.
+LIM limit of bin 2 to 1% to complete the example given.
Sequential Sorting
Sequential sorting with the same nominal can be set up in essentially the same way as for
overlap sorting, with a nominal value only defined for bin 0. However, every bin will need both
upper (
the bands –2% to –1%, ± 1%, and +1% to +2%, bin 0 has its
value,
set to +1% and its
+LIM) and lower (–LIM) limits defined. For example, to sort a particular resistor into
+LIM set to –1% and –LIM set to –2%; bin 1 has no NOM value and its +LIM is
–LIM is set to +1%.
Sequential sorting with different nominals can again be set up in essentially the same way but this
time every bin has
are symmetric then only
need to be set.
NOM set to the nominal resistor
–LIM to –1%; bin 2 has no NOM either, its +LIM is set to +2% and its
NOM set to its respective nominal. If the limits associated with each nominal
+LIM need be set, but if they are asymmetric then –LIM will also
In both schemes bin 8 can be set with the limit for the minor term, if required, exactly as
described previously.
Any parts that do not fall into the pass bins or bin 8, including any ‘gaps’ between the limits of the
sequential bins are assigned to bin 9, the general failure bin.
Storing and Recalling Sort Set–ups
Set–ups for multi–bin sorting are stored and recalled from non–volatile memory exactly as
described for simple pass/fail sorting.
19
General
The instrument can be remotely controlled via its RS232 interface.
At power-on the instrument will be in the local state with the REMote indicator off. When a
command is received the remote state will be entered and the REMote indicator will be turned on.
The keyboard is not locked out and the instrument may be returned to the local state by pressing
any key; however, the effect of this action will only remain until the instrument receives another
character from the interface, when the remote state will once again be entered.
Remote command format and the remote commands themselves are detailed in the Remote
Commands chapter.
RS232 Connector
The 9-way D-type serial interface connector is located on the instrument rear panel. The pin
connections are as shown below:
Pin Name Description
1 DCD Linked to pins 4 and 6
2 TXD Transmitted data from instrument
3 RXD Received data to instrument
4 DTR Linked to pins 1 and 6
5 GND Signal ground
6 DSR Linked to pins 1 and 4
7 RTS Linked to pin 8
8 CTS Linked to pin 7
9 - No internal connection
Remote Operation
Connect to a PC with a cable which has pins 2, 3, 5, wired plus pins 1, 4, 6 and pins 7 and 8,
linked at the PC end, see diagram. Alternatively, since the links are also made at the instrument
end, a fully-wired 1-to-1 cable may be used.
The interface parameters are fixed as follows:
RS232 Character Set
Any ASCII code can be used. Bit 7 of ASCII codes is ignored, i.e. assumed to be low. No
distinction is made between upper and lower case characters in command mnemonics and they
may be freely mixed. The ASCII control codes between 00H and 31H are ignored, except for 0AH
(Line Feed, LF) which is used as a command terminator.
Baud Rate: 9600
Start Bits: 1 Parity: None
Data Bits: 8 Stop Bits: 1
20
RS232 Remote Command Formats
Serial input to the instrument is buffered in an input queue which is filled, under interrupt, in a
manner transparent to all other instrument operations. This queue contains raw (un-parsed)
command data which is taken, by the parser, as required. Commands (and queries) are executed
in order and the parser will not start a new command until any previous command or query is
complete.
Commands (and queries) must be sent as specified in the command list and must be terminated
with the command terminator code 0AH (Line Feed, LF). Note that parameters are separated
from the command header by one space (20H) and multiple parameters are separated by
commas (2CH).
Responses to commands or queries are sent immediately; there is no output queue. The
controller must wait for the response to a command or query before the next command or query
is sent.
The instrument responds to the controller after every command either with ‘OK’ if the command
was completed successfully, or with ‘ERRnn’ if the command was not accepted; nn is the error
number, see list at the end of this section. The instrument responds to the controller after every
query as specified in the commands list. In all cases each response is terminated by 0DH
(Carriage Return, CR) followed by 0AH (Line Feed, LF).
Remote Commands
<WHITE SPACE> is defined as character codes 00H to 20H inclusive. <WHITE SPACE> is ignored
except in command identifiers. e.g. '*C LS' is not equivalent to '*CLS'.
The high bit of all characters is ignored.
The commands are case insensitive.
Command List
This section lists all commands and queries implemented in this instrument. The commands are
listed in alphabetical order within the function groups.
The following nomenclature is used:
<rmt> <RESPONSE MESSAGE TERMINATOR>, CR followed by LF
<nrf> A number in any format. e.g. 12, 12·00, 1·2 e1 and 120 e-1 are all
accepted as the number 12. Any number, when received, is converted to
the required precision consistent with the use then rounded up to obtain
the value of the command.
<nr1> A number with no fractional part, i.e. an integer.
Measurement Set-up Commands
BIASOFF Sets internal bias off.
BIASON Sets internal bias on.
FREQ <nr1> Sets the frequency as follows:
<1> sets 100Hz or 120Hz as determined by internal hardware link.
<2> sets 1kHz.
<3> sets 10kHz.
FUNC <nr1> Sets the measurement function as follows:
<0> sets Auto
<1> sets R + Q
<2> sets L + Q
<3> sets C + D
<4> sets C + R
21
HOLDOFF Sets Range Hold off.
HOLDON Sets Range Hold on.
MODE <nr1> Sets the equivalent circuit mode as follows:
<1> sets Series mode.
<2> sets Parallel mode.
ZEROCON ‘Nulls out’ residual capacitance (up to 100pF) at the measurement
terminals; the measured value is subtracted from all subsequent C + D or
C + R readings until Zero C is turned off. Can only be used with a
capacitance function already selected.
ZEROCOFF Turns off Zero C function.
Measurement Reading Commands
READALL? Returns the values of the major parameter, minor parameter and bin
number of the reading completed immediately after the command has been
passed.
The syntax of the response is <ASCII data><rmt>, where <ASCII data>
consists of the three values separated by commas.
The major and minor values are returned as a character string of the form
X=n.nnnnE±nn where X = R, L, C, Q or D and n is a decimal number. The
units are Ohms for R, Henrys for L and Farads for C.
For example:
L=1.5000E-6 is 1.5µH
C=18.000E-12 is 18pF
Q=2.56 is Q = 2.56
D=0.015 is D = 0.015
The bin number is returned in the form BIN=n, where n is a decimal
READMAJ? Returns the value of the major parameter only, in the format described
READMIN? Returns the value of the minor parameter only, in the format described
R=2.0000E+3 is 2kΩ
number. When binning is not active, NOBIN is returned.
Examples of complete responses are:
L=1.5000E-6,Q=2.18,NOBIN<rmt>
C=186.97E-6,R=0.2015,BIN=2<rmt>
R=384.30E-3,Q=0.0004,BIN=1<rmt>
above for READALL?
above for READALL?
READBIN? Returns the value of the bin number only in the format described above for
READALL?
22
Binning Commands
BINCLEAR Clears the nominal values and limits of all the bins; this has the effect of also
turning off Sort, should it be selected.
BINNOM <nr1>,<nrf> Sets the nominal of Bin <nr1> to value <nrf>; <nr1> can be 0 to 8 (9 is the
general fail bin). Note that Bin 8 is always the minor term bin (Q, D or R)
The nominal value <nrf> relates to the function selected at the time the first bin
is defined; further bins defined relate to the same function. Selecting Sort will
force that selected function.
If no nominal value is set for a bin, the nominal value for the next lowest bin will
automatically be used. The lowest numbered active bin must have its nominal
value set; Bin 0 must always be set for binning to be enabled.
BINNOM? <nr1> Returns the nominal value of bin <nr1> in the form <nrf><rmt>.
LIMHI <nr1>,<nrf> Sets the upper limit of Bin <nr1> to <nrf>%. The upper limit must be set before
the lower limit.
LIMHI? <nr1> Returns the upper limit of Bin <nr1>.
LIMLO <nr1>,<nrf> Sets the lower limit of Bin <nr1> to <nrf>%. The lower limit must be set below
the upper limit (which must have been set first). If no lower limit is set the
instrument will use the negative of the upper limit, i.e. the limits will be
symmetrical about the nominal.
LIMLO? <nr1> Returns the lower limit of Bin <nr1>.
Note: Limits may be set for bins with no nominal value; the nominal used will
be that of the next lowest bin which has a nominal set.
SORTON Enables binning (sort). Enabling sort forces the measurement function
associated with the binning set-up. Sort can only be enabled if at least one bin
has been defined.
SORTOFF Disables binning (sort).
System Commands
RST Resets the instrument to the power-up default settings.
RCL<nr1> Recalls the instrument set–up contained in store number <nr1>. Valid store
numbers are 0 - 9. Recalling store 0 sets all parameters to the power-up
default settings. An attempt to recall from a store which has not been
previously loaded with a set–up will cause an error.
SAV<nr1> Saves the complete instrument set–up in store number <nr1>. Valid store
numbers are 1 – 9.
Status Commands
*LRN?
Returns the complete set up of the instrument as a hexadecimal character data
block. The syntax of the response is LRN <data><rmt>.
To re-install the set–up return the block exactly as received, including the LRN
header at the beginning of the block, see below. The settings in the instrument
are not affected by execution of the *LRN? command.
LRN
<character data>
Install data from a previous *LRN? command. Note that the LRN header is
provided by the *LRN? response block.
Miscellaneous Commands
*IDN
?
23
Returns the instrument identification. The exact response is determined by the
instrument configuration and is of the form <NAME>,<model>, 0,<version><rmt>
where <NAME> is the manufacturer's name, <model> defines the type of
instrument and <version> is the revision level of the software installed.
Calibration Specific Commands
See Service Manual for details of calibration specific commands.
Error Numbers
The instrument responds to the controller after every command with 'OK' if the command was
completed successfully or with 'ERRnn' if the command was not accepted. Commands will not
be accepted if the command is correct but the parameters are out of range (e.g. 'FREQ 5' will
return 'ERR1') or if the command is correct but cannot be implemented (e.g. ZEROCON with
resistance selected). In the case of '?' commands the error is returned if there is nothing set up to
return, e.g. 'ERR8' if no Hi limits have been set for the selected bin. Neither 'OK' nor 'ERRnn' are
returned if the command cannot be recognised.
Error Code List
The commands associated with the various error numbers are as follows:
Error No. Command
1 FREQ <nr1>
2 FUNC <nr1>
3 MODE <nr1>
4 ZEROCON
5 ZEROCOFF
6 BINNOM <nr1>,<nrf>
7 BINNOM? <nr1>
8 LIMHI? <nr1>
9 LIMLO? <nr1>
Error 18 is returned in response to READALL? if there is no valid measurement, e.g. display
shows overrange.
Error No. Command
10 LIMHI <nr1>,<nrf>
11 LIMLO <nr1>,<nrf>
12 SORTON
13 RCL <nr1>
14 RST
15 SAV <nr1>
16 *LRN?
17 LRN <data>
18 READALL?
Maintenance
The Manufacturers or their agents overseas will provide a repair service for any unit developing a
fault. Where owners wish to undertake their own maintenance work, this should only be done by
skilled personnel in conjunction with the service manual which may be purchased directly from
the Manufacturers or their agents overseas.
Cleaning
If the instrument requires cleaning use a cloth that is only lightly dampened with water or a mild
detergent.
WARNING! TO AVOID ELECTRIC SHOCK, OR DAMAGE TO THE INSTRUMENT, NEVER
ALLOW WATER TO GET INSIDE THE CASE. TO AVOID DAMAGE TO THE CASE NEVER
CLEAN WITH SOLVENTS.
Connector Contact Cleaning
Ensure the contact surfaces of the Kelvin connectors are free from contamination. The contacts
of both the built–in connectors and the axial adaptors are made of high quality stainless steel but
they can pick up contamination from the environment or from component leads inserted into the
connector. Occasionally clean the connectors by inserting a piece of clean stiff card between
them and lightly pushing back and forth. In extreme cases the card may be moistened with a little
suitable cleaning solution.
24
Sécurité
Cet instrument est de Classe de sécurité 1 suivant la classification IEC et il a été construit pour
satisfaire aux impératifs EN61010-1 (impératifs de sécurité pour le matériel électrique en vue de
mesure, commande et utilisation en laboratoire). Il s'agit d'un instrument d'installation Catégorie II
devant être exploité depuis une alimentation monophasée habituelle.
Cet instrument a été soumis à des essais conformément à EN61010-1 et il a été fourni en tout
état de sécurité. Ce manuel d'instructions contient des informations et avertissements qui doivent
être suivis par l'utilisateur afin d'assurer un fonctionnement en toute sécurité et de conserver
l'instrument dans un état de bonne sécurité.
Cet instrument a été conçu pour être utilisé en interne dans un environnement de pollution
Degré 2, plage de températures 5°C à 40°C, 20% - 80% HR (sans condensation). Il peut être
soumis de temps à autre à des températures comprises entre +5°C et −10°C sans dégradation
de sa sécurité. Ne pas l'utiliser lorsqu'il y a de la condensation.
Toute utilisation de cet instrument de manière non spécifiée par ces instructions risque d'affecter
la protection de sécurité conférée. Ne pas utiliser l'instrument à l'extérieur des tensions
d'alimentation nominales ou de la gamme des conditions ambiantes spécifiées.
AVERTISSEMENT! CET INSTRUMENT DOIT ETRE RELIE A LA TERRE
Toute interruption du conducteur de terre secteur à l'intérieur ou à l'extérieur de l'instrument
rendra l'instrument dangereux. Il est absolument interdit d'effectuer une interruption à dessein. Ne
pas utiliser de cordon de prolongation sans conducteur de protection, car ceci annulerait sa
capacité de protection.
Lorsque l'instrument est relié au secteur, il est possible que les bornes soient sous tension et par
suite, l'ouverture des couvercles ou la dépose de pièces (à l'exception de celles auxquelles on
peut accéder manuellement) risque de mettre à découvert des pièces sous tension. Il faut
débrancher ke cordon secteur de l'appareil avant de l'ouvrir pour effectuer des réglages,
remplacements, travaux d'entretien ou de réparation.
Eviter dans la mesure du possible d'effectuer des réglages, travaux de réparation ou d'entretien
lorsque l'instrument ouvert est branché au secteur, mais si c'est absolument nécessaire, seul un
technicien compétent au courant des risques encourus doit effectuer ce genre de travaux.
S'il est évident que l'instrument est défectueux, qu'il a été soumis à des dégâts mécaniques, à
une humidité excessive ou à une corrosion chimique, la protection de sécurité sera amoindrie et il
faut retirer l'appareil, afin qu'il ne soit pas utilisé, et le renvoyer en vue de vérifications et de
réparations.
Remplacer les fusibles uniquement par des fusibles d'intensité nominale requise et de type
spécifié. Il est interdit d'utiliser des fusibles bricolés et de court-circuiter des porte-fusibles.
Eviter de mouiller l'instrument lors de son nettoyage.
Les symboles suivants se trouvent sur l'instrument, ainsi que dans ce manuel.
ATTENTION - se référer à la documentation ci-jointe; toute utilisation
incorrecte risque d'endommager l'appareil.
Courant alternatif (c.a.)
25
Tension d'alimentation secteur
La tension dalimentation de l'instrument est indiquée à l'arrière. S'il est nécessaire de la modifier
de 230V à 115V ou vice-versa, procéder comme suit :
1. Débrancher l'instrument du secteur d'alimentation.
2. Retirer les 6 vis qui maintiennent le couvercle supérieur et soulever ce couvercle en
notant la position du connecteur du câble plat.
3. Retirer les 4 vis qui maintiennent la carte à circuits imprimés sur le châssis et libérer la
carte.
4. Changer les liaisons zéro ohm appropriées à côté du transformateur de la carte :
LK4 uniquement pour le fonctionnement à 230V
LK3 et LK5 uniquement pour le fonctionnement à 115V
Noter que si le changement de tension de fonctionnement s'accompagne d'un
changement de fréquence de la tension, le rejet du mode commun optimum de la tension
du secteur peut être réalisé en définissant la sélection interne de 100/120Hz sur 100Hz
pour une alimentation à 50Hz et sur 120Hz pour une alimentation à 60Hz. Cette opération
se réalise en agissant sur l'état de la liaison LK2 située immédiatement sous le module
oscillateur de la carte de circuit principale. Sans liaison de court-circuit sur les broches, la
fréquence est fixée à 100Hz ; avec cette liaison, elle est de 120Hz. Le réglage en usine
de 230V est de 100Hz, et en 115V, il est de 120Hz. Si le réglage en usine de LK2 est
modifié, l'instrument doit être recalibré à la nouvelle fréquence (le calibrage simultané à
100Hz et 120Hz est impossible).
Installation
5. Remonter la carte sur le châssis en s'assurant que toutes les connexions
(particulièrement la terre) sont rétablies et remonter le couvercle supérieur.
6. Pour satisfaire aux exigences de sécurité, la tension d'alimentation secteur indiquée à
l'arrière de l'instrument doit être modifiée pour indiquer la nouvelle tension opérationnelle.
7. Changer le fusible afin qu'il corresponde à la nouvelle tension de fonctionnement (voir ciaprès).
Fusible
Le fusible approprié doit être installé en fonction de la tension de fonctionnement sélectionnée.
Pour le fonctionnement à 230V, utiliser un HBC 125mA (T) 250V.
Pour le fonctionnement à 115V, utiliser un HBC 250mA (T) 250V.
S'assurer que seuls les fusibles de la tension nominale et du type requis soient utilisés.
L'utilisation de fusibles «maison» et le court-circuitage des porte-fusibles est strictement interdit.
Cordon d'alimentation
Lorsqu'un cordon d'alimentation de rallonge à trois conducteurs est fourni, il doit être utilisé
comme suit :
Marron - Phase
Bleu - Retour
Vert/Jaune - Terre
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AVERTISSEMENT ! CET INSTRUMENT DOIT ETRE RELIE A LA TERRE
Toute interruption du conducteur de terre secteur à l'intérieur ou à l'extérieur de l'instrument
rendra l'instrument dangereux. Toute interruption intentionnelle est absolument interdite.
Connexion des composants
Les fils du composant sous test sont branchés aux connecteurs Kelvin sur le dessus de
l'instrument. Les composants à sorties axiales doivent être insérés dans les adaptateurs fournis,
lesquels sont eux-mêmes branchés aux connecteurs Kelvin. Les deux formes de connexion
permettent le contact véritable à quatre bornes du composant, pour garantir la mesure précise
des composants de faible impédance.
Les fils des composants à sorties radiales peuvent être insérés directement dans les connecteurs
à ressort. Pour les fils fragiles, ouvrir les connecteurs en appuyant sur leur actionneur.
De la même manière, les adaptateurs axiaux peuvent être insérés directement dans les
connecteurs principaux ; régler la position des adaptateurs en fonction de la longueur des fils et
de celle du corps du composant.
Vérifier que les surfaces de contact des connecteurs Kelvin soient exemptes de contamination.
En cas de doute, consulter la section Maintenance.
Composants montés en surface
Branchez le module d'interface des pinces de montage en surface optionnelles dans les
connecteurs Kelvin. Un véritable contact quatre bornes est assuré au niveau des pinces.
Connexions distantes
Un gabarit de test à distance peut être connecté via les connecteurs BNC au module externe
d'interface optionnel qui s'insère dans les connecteurs Kelvin sur le dessus de l'instrument. Les
connecteurs sont nommés High Drive, High Sense, Low Sense et Low Drive. Les blindages des
câbles coaxiaux Drive doivent être branchés ensemble à l'extrémité distante et reliés à l'écran et
au boîtier du gabarit externe. Les blindages des câbles Sense doivent être isolés à la fois l'un de
l'autre et aussi de l'écran du gabarit de test.
Connexions
RS232
Les câbles jusqu'à un mètre de longueur sont peu susceptibles de poser des problèmes, mais les
câbles reliés à un gabarit externe doivent être aussi courts que possible et la précision des
mesures doit être vérifiée à toutes les fréquences de test ainsi que sur la plage de valeurs
mesurée avant d'être considérées comme fiables.
Connecteur D à 9 broches pour contrôle à distance par ordinateur individuel :
Broche Nom Description
1 DCD Reliée aux broches 4 et 6
2 TXD Données transmises depuis l'instrument
3 RXD Données reçues par l'instrument
4 DTR Reliée aux broches 1 et 6
5 GND Terre
6 DSR Reliée aux broches 1 et 4
7 RTS Reliée à la broche 8
8 CTS Reliée à la broche 7
9 – Aucune connexion interne
Relier ce connecteur à un PC à l'aide d'un câble dont les broches 2, 3 et 5 sont câblées entre les
deux extrémités alors que, côté PC, les broches 1, 4, 6 sont reliées entre elles, de même que 7 à
8. Ces liaisons entre broches existant déjà dans l'instrument, un câble blindé fil par fil peut être
utilisé.
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Cette section présente l'utilisation générale de l'instrument. Bien que ses fonctions de base
soient évidentes à l'aperçu du clavier, les utilisateurs souhaitant avoir recours à toutes les
performances et à un degré maximal de précision sont invités à lire ce manuel et les sections
Principes de mesure attentivement.
Mise en marche
Mettre en marche l'instrument à l'aide de l'interrupteur ON/OFF à l'arrière.
A l'allumage, l'instrument exécute une courte procédure d'autotest, affiche la version du logiciel et
attend en mode Auto qu'un composant soit mesuré. S'il est allumé alors qu'un composant lui est
connecté, il le détecte automatiquement et le mesure.
Pour couper entièrement l'instrument du secteur, débrancher le cordon d'alimentation à l'arrière
de l'instrument ; s'assurer que la déconnexion est facilement accessible. Débrancher l'instrument
du secteur lorsqu'il est inutilisé.
Affichage
Fonctionnement
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En utilisation normale, l'instrument affiche le paramètre majeur (L, C ou R) à l'aide des 5 chiffres
de gauche, et le paramètre mineur (Q, D ou R) à l'aide des 5 chiffres de droite. Les paramètres
affichés sont indiqués au-dessus de leurs valeurs numériques respectives et les unités du
paramètre s'affichent sur la droite de la valeur elle-même. Un test d'affichage qui allume tous les
chiffres peut être effectué : pour ce faire, maintenir enfoncée une touche quelconque du clavier
au moment de la mise sous tension.
La précision de base est de 0,1% et, pour la plage d'impédance pour laquelle cette précision est
garantie (voir Spécifications), l'instrument distingue la plage automatiquement pour fournir
typiquement entre 5 000 et 50 000 décomptes de résolution d'affichage. Si la valeur mesurée se
trouve en dehors de la plage pour laquelle la précision de 0,1% est garantie (à la fréquence de
mesure sélectionnée) l'indicateur d'unités (kΩ, pF, etc.) clignote pour le signaler. Si l'indicateur de
fréquence clignote également, le fait de modifier la fréquence peut ramener le composant mesuré
dans la plage de 0,1% de précision. Le fait, par exemple, de mesurer 680pF à la fréquence Auto
par défaut de 1kHz fait clignoter à la fois l'indicateur d'unité (pF) et de fréquence ; changer la
fréquence à 10kHz ramène la valeur de 680pF dans la plage de précision de 0,1% de
l'instrument, et les voyants cessent de clignoter.
Pendant la configuration et la fonction de tri, l'affichage a d'autres fonctions qui sont expliquées à
la section Tri des composants.
Touches et indicateurs de mesure
Fréquence
Le fait d'appuyer sur la touche Freq (Fréquence) règle la fréquence de mesure sur 100/120Hz,
1kHz ou 10kHz.
Remarque : pour une alimentation à 50Hz, la fréquence de test la plus basse est généralement
de 100Hz ; à 60Hz d'alimentation elle est généralement de 120Hz, voir la section Installation.
Le fait d'appuyer sur cette touche fait passer la fréquence de 100/120Hz à 1kHz puis à 10kHz et
de retour à 100/120Hz. Le voyant indique le réglage utilisé. S'il clignote, il indique qu'une autre
fréquence pourrait donner une mesure plus précise du composant du type et de la valeur en
cours.
Mode
Cette touche sélectionne le mode circuit série ou circuit parallèle équivalent à afficher. Voir la
section Principes de mesure. Si l'un des voyants clignote, il indique que l'autre mode de
fonctionnement convient mieux au composant du type et de la valeur en cours de mesure. Si le
mode Auto (automatique ) a été sélectionné, le Mode ne peut être modifié sans sélectionner
préalablement L, C ou R.
Bias
Cette fonction applique 2 Volts CC aux bornes de test pour polariser les capacités électrolytiques
conformément à la polarité indiquée sur les connecteurs Kelvin. Notez que l'application d'une
polarisation aux résistances ou aux inductances peut entraîner une erreur de mesure du fait
d'une surcharge interne. Les tensions de polarisation jusqu’à 50 V CC peuvent être appliquées
de manière externe : consulter la section Polarisation externe du chapitre Principes de mesure.
Zero C
Lorsque des capacités sont mesurées, le fait d'appuyer sur cette touche avant d'insérer le
composant à tester met l'affichage de capacité à zéro et élimine ainsi la capacité du gabarit de
test. Jusqu'à 100pF de capacité résiduelle peut être ainsi éliminée. Le facteur de correction est
perdu lorsque le pont est éteint. La fonction Zero C ne peut être utilisée que lorsqu'une capacité
est mesurée ; si une autre fonction est sélectionnée, l'instrument affiche
secondes et la commande est ignorée.
not C pendant 2
R+Q, L+Q, C+D, C+R
Règle l'instrument pour afficher le paramètre majeur à gauche et le paramètre mineur à droite.
Auto
En mode Auto, l'instrument détecte automatiquement si le composant en cours de mesure est
une résistance, une capacité ou une inductance, et règle l'instrument pour afficher les paramètres
de test du composant automatiquement. Il convient de noter que les composants "imparfaits" tels
que les inductances à résistance élevée en série peuvent être détectés de manière incorrecte en
mode Auto : il est alors nécessaire de régler manuellement la fonction appropriée. En mode Auto,
la fréquence de mesure peut être modifiée (en appuyant sur la touche Freq) mais la sélection de
mode Series/Parallel est maintenue à sa valeur par défaut pour le type de composant en cours.
Voir la section Principes de mesure. Pour passer du mode série au mode parallèle, ou vice–
versa, il est d'abord nécessaire de quitter le mode Auto en sélectionnant la fonction appropriée
(R+Q, L+Q, etc.) ; le mode peut alors être modifié à l'aide de la touche Mode.
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