Aim TTi LCR400 INSTRUCTION MANUAL

LCR400

Precision LCR Bridge

INSTRUCTION MANUAL

Table of Contents

Introduction 1 Specification 2 Safety 4 Installation 5 Connections 6 Operation 7 Measurement Principles 9 Component Sorting 13 Remote Operation 17 Remote Commands 18 Maintenance 21

Instructions en Francais 22 Bedienungsanleitung auf Deutsch 43 Istruzioni in Italiano 65 Instrucciones en Español 86

Introduction

The LCR 400 Precision Bridge provides a fast, convenient and accurat e m eans 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 f r ont panel keyboard or by RS232 link to a PC which can be used to set up all measurement f unct ions.

The LCR400 can be programmed to sort a r ange 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 inst r um ent 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–t er minal test fixture or plug–in axial adaptor providing true contact resistance fr ee m eas ur em ents for low impedance components.

The capacitance (up to 100pf) introduced by an external test f ixture can be c ancelled out permitting high impedance measurem ents t o be made with confidence.

Parameters Measured:

R, L, C, D & Q.

Measurement Modes:

Series or parallel equivalent circuit.

function nulls out up to 100pF of stray capacitance in the test fixture.

± 0.01%. 120Hz instead of 100Hz by factory option f or 60Hz operation.

and Resolution:

Parameter

Range

0.1mΩ − 990MΩ

0.001pF − 99000µF

0.001 − 999

100/120Hz

1kHz

10kHz

0.1Ω − 20MΩ

0.1Ω − 10MΩ

0.1Ω – 500kΩ

200µH − 9900H

20µH − 1000H

2µH − 100H

500pF − 20000µF

50pF − 2000µF

5pF − 200µF

or L = 10mH – 50H

or L = 1mH – 2.5H

or L = 100µH – 250mH

Capacitance accuracies apply after null.

Measurement Update Rate:

2.5 readings per second.

Type:

Comparison with multiple limits set up from the keyboard or PC via RS232 interface.

Binning:

Up to 8 Pass bins for the major paramet er, plus minor parameter Fail and general Fail bins.

Specification

Specifications apply for 18ºC − 28ºC ambient after 30 minute warm-up.

Functions

Measurement Functions: Fully autoranging including selection between L, C and R. The Zero C

Measurement Frequency: User selectable to be 100Hz, 1kHz or 10kHz; frequency accuracy

Measurement Ranges

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

0.001µH − 9900H

2Ω − 1MΩ

0.4Ω − 5MΩ

4mH – 500H 800µH – 2500H

10nF − 1000µF 2nF − 5000µF

2Ω − 500kΩ

0.4Ω − 2MΩ

400µH − 50H 80µH – 250H

1nF − 100µF 200pF − 500µF

2Ω − 50kΩ

0.4Ω − 200kΩ

40µH − 5H 8µH – 25H

100pF − 10µF 20pF − 50µF

Q & D 0.25% ± 1 digit

0.25 − 4.0 for C = 40nF – 100µF

Limits Comparator (Sort Mode)

0.25 − 4.0 for C = 10nF – 10µF

0.25 − 4.0 for C = 1nF – 1µF

Maximum display count 50,000.

Simultaneous display of Pass/Fail status with Bin No. in Sort mode.

Component Connection:

4-terminal connection for both radial and axial devices.

Component:

0·3Vrms.

Bias Voltage:

Switchable 2V polarising voltage for measuring electrolytic capacitors.

energy.

results data-logging on the PC.

Keyboard:

Full numeric keyboard for entry of limits data.

Non-Volatile Memory:

Up to 9 complete set ups stored in non-volatile memory.

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 Degr ee 2.

via http://www.aimtti.com/support (serial no. needed).

Size:

365 x 240 x 95 mm, including feet.

Weight:

2.9 kg.

PC logging software.

Display

Display Ty pe: Dual 5-digit 0·56” LEDs with range and f unct ion indicat ion.

Display Functions: Simultaneous display of R + Q, L + Q, C + D, or C + R in normal

measurement modes. Prompts to change freq uency or m ode t o im pr ove accurac y.

Inputs

Maximum Voltage on

Input Protection: The instrument has been designed to withstand direct connection of

capacitors charged up to 50V DC with up to 1 Joule ( ½ CV

) of stored

Interfaces

RS232: Serial link to PC permitting range/ function control, limits setting and

General

Power: 220V-240V AC or 110V-120V AC ±10%, 50/60Hz, adjustable internally;

Safety & EMC: Complies with EN61010-1 & EN61326-1.

For details, request the EU Declaration of Conformity for this instrument

Options: Remote 4–terminal measurement interface.

4–terminal surface mount tweezers. Kelvin Clip set.

incorrect operation may damage the instr um ent.

Safety

This instrument is Safety Class I accor ding 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 Ins tallation Category II instrument intended for operation from a nor m al single phase supply.

This instrument has been tested in accordanc e 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 r etain the inst r um ent in a safe condition.

This instrument has been designed f or 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 bet ween +5° and −10°C without degradation of its safety. Do not operate while condensation is present.

Use of this instrument in a manner not spec ified by these instructions may impair the safety protection provided. Do not operate the instrum ent outside its rat ed supply voltages or environmental range.

WARNING! THIS INSTRUMENT MUST BE EARTHED

Any interruption of the mains earth conduct or inside or outside t he inst r um ent will make the instrument dangerous. Int ent ional inter ruption 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, m aint enance or r epair.

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 c ur r ent 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 m anual:−

Caution −refer to t he acc om panying documentation,

alternating current.

Mains Operating Voltage

The operating voltage of the instr um ent is shown on the rear panel. Should it be necessary to change the operating voltage f r om 230V t o 115V or vice-versa, proceed as follows:

1. Disconnect the instrument fr om all voltage sources.

2. Remove the 6 screws which hold the case upper to the chassis and lift off, noting t he flat cable connector positions.

3. Remove the 4 screws securing the power supply pcb to the chassis and lift the pcb f r ee.

4. Change the appropriate zero-ohm links beside the t r ans former on the pcb:

Link LK4 only for 230V operation Link LK3 and LK5 only for 115V operation Note that, if the chang e 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 f it t ed t o 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, ens ur ing all connections (especially safety earth) are remade

6. To comply with safety standard r equirements the operating voltage marked on the r ear

7. Change the fuse to suit t he new operating voltage, see below.

Fuse

The correct time-lag fuse must be fitted f or t he s elect ed oper at ing 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

Connect the instrument to the AC supply using the mains lead provided. Should a mains plug be required for a differ ent m ains out let soc ket, a suitably rated and approved mains lead set should be used which is fitted with the required wall plug and an IEC60320 C13 connector for t he instrument end. To det er m ine t he m inimum current rating of t he lead-s et for the intended AC supply, refer to the power rating inf or m ation on the equipment or in the Specification.

as before, and refit the case upper.

panel must be changed to clearly show the new voltage setting.

WARNING! THIS INSTRUMENT MUST BE EARTHED

Any interruption of the mains earth conduct or inside or outside t he inst r um ent will make the instrument dangerous. Int ent ional inter ruption is prohibited.

Name

Description

DCD

Linked to pins 4 and 6

TXD

Transmitted data from instrument

RXD

Received data to instrument

DTR

Linked to pins 1 and 6

GND

Signal ground

DSR

Linked to pins 1 and 4

RTS

Linked to pin 8

CTS

Linked to pin 7

–

No internal connection

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–t er m inal 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; adj ust 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 c ontaminat ion. I f in doubt, refer to the Maintenance section.

Surface Mount Components

Plug the interface module of t he 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 instrum ent . 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 t he external jig. The screens of the Sense leads should be isolated both from each other and from t he 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 m eas ur em ents chec ked 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:

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 m ade within the instr ument, a fully–wired 1–to–1 cable may be used.

This section covers general use of the instrument. Although the basic capabilities are largely obvious from the keypad functions, users r equiring full performance and acc ur acy 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 r ear panel. At switch on the instrument runs a short inter nal 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 c om ponent .

To f ully disconnect from the AC supply unplug the mains cord from the back of the instr um ent 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

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, f or the impedance range for which this accuracy is guaranteed (see Specification) the instrument will autorange to g ive typically between 5,000 and 50,000 counts of display resolution. If the m eas ur ed value is outside the rang e within which

0.1% accuracy is guaranteed (at the m easur ement frequency selected) the units indicator (kΩ,

pF, etc.) will flash t o show this. I f the frequency indicator is also f lashing , changing the frequency range may bring the component being m eas ur ed within the r ange of the instruments 0.1% accuracy specification. For example, measuring 680pF at t he 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 measur em ent 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 10k Hz 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 t hat 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 t o r esist ors or inductors may cause a measurement error because of internal overload. Bias voltages up to 50V DC can be applied externally, s ee t he External Bias section of the Measurement Principles chapter.

Zero C

When measur ing c apacitors, 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 correct ion 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 t he 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 t he Freq key) but the Series/Parallel mode selection is held at the default selection for that component type, see Measurement Principles section. To chang e 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.) ; t he m ode c an t hen be c hanged 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 t im e bet ween measurem ents of similar value components.

Note that DUT voltage and current measurement are individually auto–ranged f or optimum accuracy and resolution; the processor then deter m ines t he m eas ur em ent unc er tainty 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 Rang e 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.

Lpj

LpRpj

Lsj

RsZs

LpQRp

jRsZs

−=

RpCpj

RpCp

RsCsD

CpDCs

(

where

ω =

2πf

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 str es sed t hat 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 lat er.

The Models used by the LCR400 are as follows:

Measurement Principles

(D is also known as tanδ)

Resistors

All resistors have parasitic impedances, both inductance and capacitance and distributed effects of both. Fortunately, however, in normal use t hes e parasitic effects are usually very small compared with the resistance.

The LCR 400 provides the opportunity to evaluate the series and parallel components of resistor s at 100Hz and 1kHz and 10kHz.

Some types of resistor have more prominent parasit ic 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 t he 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 t ypically around 0.25pF. This usually only becomes significant on high value resistors or/ and at high frequencies. Bifilar wound resistors m ay 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

frequencies requires a m or e c om plex equivalent circuit t han t he s im ple two component ser ies or parallel circuits discussed here. In practice the solution is to select com ponent types to match the frequency range of the application.

For the majority of resistor s , 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, t he s er ies 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 m ay be mor e appr opriate.

Normally R+Q should be selected for resistors; t he 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 significant ly to thos e 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. Som e t ypes 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 negat ive 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 ter m s 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 res istance are usually negligible, but on high value electrolytics, used to smooth power supplies, it c an be very important. The series resistance of such devices is often a manufacturers specified parameter.

For most capacitors, other than hig h value electrolytics, the parallel equivalent circuit will give the capacitance that matches the manufactur er s 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 manufactur er spec ifies Equivalent Series Resistance (ESR) the series equivalent circuit should be used.

The LCR 400 provides the means to investigate the losses of capacitor s eit her in t erms 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 measurem ent is outside its maximum accuracy range by flashing the units annunciator; if accuracy can be improved by changing the measurement f r equency the frequency annunciator will also flash, see Display section.

such capacitors. Higher voltage or higher energ y may result in dam age to the instrument.

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) t o 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 m odule ar e m ar ked 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 measur em ents with a DC bias, especially at high bias voltages; failure to do so may result in possible user injury and damag e t o 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 char ged up to 50V DC with up to 1 Joule of stored energy ( ½ CV

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 t he induct or. There is capacitance between each turn of conductor and every other turn. The magnetic f ield of an inductor can extend outside the physical package of the component.

); it should not, however, be used to routinely discharge

In its simplest form the resistance can be r epr es ent ed as a r esistor 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.

Resistor

Series

Inductor

Series

Capacitor <1µF

Parallel

Capacitor >1µF

Series

On high value inductors, such as transf or m er s 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 f ield, whilst usually negligible in the case of torroids, laminated core inductors and pot core inductors, can be sig nificant 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 t he apparent inductance of the component. Conversely any ferro-magnetic material in the immediate ar ea of the component can have the effect of incr easing the apparent inductance. In extreme cases the inductance of a com ponent c an appear t o 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 accur ac y range by flashing the units annunciator; if accuracy can be improved by changing the measurement freq uency 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, capacitor s and induct or s .

In Auto mode the bridge uses the following models.

These will provide the parameters that will match data sheet values for most components.

The LCR 400 provides comprehensive facilities for sort ing components into ‘bins’ according to value. The parameters for each bin can be defined fr om t he 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 quit e 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 m aj or param et er ; bin 8 can be used to set limits for the minor parameter only (D, Q or R) and bin 9 is the general f ail 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 rec all 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.

Simple Pass / Fail Sorting

To set up sim ple pass/fail sorting, first select t he 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 ent er 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 opt ion 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 t o be clear ed s elect and press Enter; the display should show the message the right–hand display, ready for the next step. I f 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 eas ier, all the bins can be cleared by using

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 f ail bin.

Press Bin No. until the right–hand display.

CLEAr ALL? before bin 0 is set. Bin 8 can be used to set limits for the minor

Setting Nominal Value

With bin0 displayed, press t he 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 enter ed value simply enter a new value and press Enter again.

CLEAr? with the Bin No. key

CLEAr donE and then binX in

CLEAr ALL?

binX shows in the display. Pr ess 0 to select bin 0; bin0 should show in

Setting Limits

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 fr om t he nom inal allowed for a pass com ponent , 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 chang e 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 fr om 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 lim it 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

–LIM above

± key. Note also that the limits need not be symmetrical and can

–LIM) can be set above the upper limit (+LIM) but exiting set–up m ode and

Err bin0.

Minor Parameter Limits

To set t he m inor paramet er lim it (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 indicat or ( Q , D or R) will show in the right–hand side of the display and the limit value should then be enter ed 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 t o bin 9, t he general fail bin.

Using Sort

Having set up bin 0, press Bin No. unt il 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 percentag e 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 stor e 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 s et –up pr ess 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 factor y default settings; these can be loaded by pressing, Recall, 0, Enter. Memory 0 cannot be overwritten by pressing Store, 0, Enter and c annot therefore be used to store binning information.

Multiple Bin Sorting

The LCR400 supports two different schemes for m ult iple bin sort ing, overlap and sequential. Overlapping (or nested) bins have one nominal value and progressively larger symmetr ical

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 diff er ent nom inal 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.

donE to indicate that the

Multiple bin sort schemes can be quite complicated; it is therefore a good idea to write down the binning set–up before progr am m ing is started and to save the set–up once programming is complete.

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 t his t ype of binning first select the measurem ent type to be made, e.g. R + Q, set the measurement freq uency and select ser ies or parallel mode as r equired.

Select bin 0 and set the nominal value and tightest tolerance t o 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 t he limits are s ymmet rical, 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 Err bin0.

+LIM to 0.1%; if

+LIM to 0.5%;

Set the Set the minor term limit (Q in the c ase of R + Q measurements) in bin 8 if req uired; 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 g iven.

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% t o + 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 ag ain be set up in ess ent ially the same way but this time every bin has

nominal are symmetric then only will also 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

+LIM need be set, but if they are asymmetr ic t hen –LIM

In both schemes bin 8 can be set with the limit for t he 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 g ener al failure bin.

Storing and Recalling Sort Set–ups

Set–ups for multi–bin sorting are st ored and recalled from non–volatile memory exactly as described for simple pass/fail sort ing .

Name

Description

DCD

Linked to pins 4 and 6

TXD

Transmitted data from instrument

RXD

Received data to instrument

DTR

Linked to pins 1 and 6

GND

Signal ground

DSR

Linked to pins 1 and 4

RTS

Linked to pin 8

CTS

Linked to pin 7

9 - No internal connection

Baud Rate:

9600

Start Bits: 1

Parity: None

Data Bits: 8

Stop Bits: 1

General

The instrument can be remotely controlled via its RS232 interfac e. 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 instr um ent may be returned to the local state by pressing any key; however, the effect of t his act ion will only remain until the instrument receives another character from the int er face, 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 r ear panel. The pin connections are as shown below:

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, s ince t he link s ar e also m ade at the instrument end, a fully-wired 1-to-1 cable may be used.

The interface parameters ar e 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 t hey 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.

<rmt>

<RESPONSE MESSAGE TERMINATOR>, CR followed by LF

the value of the command.

<nr1>

A number with no fractional part, i.e. an int eger.

BIASOFF

Sets internal bias off.

BIASON

Sets internal bias on.

<3> sets 10kHz.

<4> sets C + R

RS232 Remote Com m and 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 s pecified in the command list and must be terminated with the command terminator code 0AH (Line Feed, LF). Not e t hat parameters are separated from the command header by one space (20H) and m ult iple paramet er s ar e s eparated by commas (2CH).

Responses to commands or queries are sent im m ediat ely; ther e is no out put queue. The controller must wait for the response to a command or query before the next comm and 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. I n all cases eac h r espons e is t er m inat ed by 0DH (Carriage Return, CR) followed by 0AH (Line Feed, LF).

Remote Commands

<WHITE SPACE> is defined as c har acter codes 00H to 20H inclusive. <WHITE SPACE> is ig nored

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 inst r um ent. The commands are listed in alphabetical order within the function groups.

The following nomenclature is used:

<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

Measurement Set-up Commands

FREQ <nr1> Sets the frequency as follows:

<1> sets 100Hz or 120Hz as determined by internal hardware link. <2> sets 1kHz.

FUNC <nr1> Sets the measurement function as follows:

<0> sets Auto <1> sets R + Q <2> sets L + Q <3> sets C + D

HOLDOFF

Sets Range Hold off.

HOLDON

Sets Range Hold on.

<2> sets Parallel mode.

capacitance function already selected.

ZEROCOFF

Turns off Zero C function.

been passed.

consists of the three values separated by commas.

units are Ohms for R, Henrys for L and Farads for C.

For example:

R=2.0000E+3 is 2kΩ

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

R=384.30E-3,Q=0.0004,BIN=1<rmt>

above for READALL?

READALL?

MODE <nr1> Sets the equivalent circuit mode as follows:

<1> sets Series 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

Measurement Reading Commands

READALL? Returns the values of t he major parameter, minor parameter and bin

number of the reading complet ed im m ediat ely after t he c om m and has

The syntax of the response is <ASCII data><rmt> , where <ASCII data>

The major and minor values are returned as a char ac t er s t r ing of the form

X=n.nnnnE±nn where X = R, L, C, Q or D and n is a decim al number. The

The bin number is returned in the form BIN=n, where n is a decimal

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>

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

READBIN? Returns the value of the bin number only in the format described above for

turning off Sort, should it be select ed.

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>.

before the lower limit.

LIMHI? <nr1>

Returns the upper limit of Bin <nr1>.

symmetrical about the nominal.

LIMLO? <nr1>

Returns the lower limit of Bin <nr1>.

be that of the next lowest bin which has a nominal set.

has been defined.

SORTOFF

Disables binning (sort).

RST

Resets the instrument to the power-up default settings.

previously loaded with a set–up will cause an error.

numbers are 1 – 9.

instrument are not affected by execution of the *LRN? command.

provided by the *LRN? response block.

instrument and <version> is the revision level of the software installed.

Binning Commands

BINCLEAR Clears the nominal values and limits of all the bins; this has the effect of also

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 f ir st bin

is defined; further bins defined relate to the same function. Select ing Sort will force that selected f unc t ion.

If no nominal value is set for a bin, the nom inal value for t he next lowest bin will automatically be used. The lowest numbered active bin must have its

LIMHI <nr1>,<nrf> Sets the upper limit of Bin <nr1> to <nrf>%. The upper limit must be set

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

Note: Limits may be set for bins with no nominal value; the nominal used will

SORTON Enables binning (sort). Enabling sort forces the measurement func t ion

associated with the binning set-up. Sort can only be enabled if at least one bin

System Commands

RCL<nr1> Recalls the instrument set–up contained in store num ber < nr 1> . Valid store

numbers are 0 - 9. Recalling store 0 sets all parameter s to the power-up default settings. An attempt to recall from a st ore which has not been

SAV<nr1> Saves the complete instrument set–up in store number <nr1>. Valid store

Status Commands

*LRN?

Returns the complete set up of t he inst r ument 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 t he block, see below. The settings in the

LRN

Install data from a previous *LRN? command. Note that t he LRN header is

Miscellaneous Commands

*IDN ?

Returns the instrument identif icat ion. The exact response is det er m ined by the instrument configurat ion and is of the form <NAME>,<model>, 0,< version>< r m t> where <NAME> is the manufacturer's name, <m odel> defines the type of

Error No.

Command

FREQ <nr1>

FUNC <nr1>

MODE <nr1>

ZEROCON

ZEROCOFF

BINNOM <nr1>,<nrf>

BINNOM? <nr1>

LIMHI? <nr1>

LIMLO? <nr1>

Error No.

Command

LIMHI <nr1>,<nrf>

LIMLO <nr1>,<nrf>

SORTON

RCL <nr1>

RST

SAV <nr1>

*LRN?

LRN <data>

READALL?

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 comm and was completed successfully or with 'ERRnn' if the comm and was not accept ed. Commands will not be accepted if the command is correc t 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 c annot be r ecognised.

Error Code List

The commands associated with the various error numbers ar e as follows:

Error 18 is returned in response to READALL? if ther e is no valid measurem ent, e.g. display shows overrange.

The Manufacturers or their ag ents 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 r equires cleaning use a cloth that is only lightly dampened with water or a mild detergent.

WARNING! TO AVOI D EL ECTRIC 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 c ontaminat ion. 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 for t h. In extreme cases the card may be moistened with a little suitable cleaning solution.

Maintenance

incorrecte risque d'endommager l'appareil.

Sécurité

Cet instrument est de Classe de sécurité 1 suivant la classif icat ion I EC et il a ét é construit pour satisfaire aux impératifs EN61010-1 (impérat ifs 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 ut ilisé en inter ne dans un environnem ent de pollution Degré 2, plage de températur es 5°C à 40°C, 20% - 80% HR (sans condensation). Il peut être soumis de temps à autre à des températures c om pr ises entre +5°C et −10°C sans dégradation de sa sécurité. Ne pas l'utiliser lorsqu'il y a de la condensation.

Toute utilisat ion de cet inst r um ent de manière non spécifiée par ces instructions risque d'affecter la protection de sécurité conférée. Ne pas utiliser l'inst r um ent 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 inter r uption du conducteur de terre secteur à l'intérieur ou à l' extér ieur de l' inst r ument rendra l'instrument dangereux. I l est absolum ent int er dit d' effectuer une interruption à dessein. Ne pas utiliser de cordon de prolongation sans conducteur de protect ion, car ceci annulerait sa capacité de protection.

Lorsque l'instrument est r elié au sect eur, 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 met tre 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 rég lages, travaux de réparation ou d'entretien lorsque l'instrument ouvert est br anc hé au secteur, mais si c'est absolument nécessaire, seul un technicien compétent au courant des risques encour us doit effectuer ce genre de travaux.

S'il est évident que l'instr um ent est défectueux, qu'il a été soumis à des dég âts m écaniques, à une humidité excessive ou à une corrosion chimique, la protection de sécurité ser a 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 f usibles d' intens it é nom inale requise et de type spécifié. Il est interdit d'ut iliser des fusibles bricolés et de court-circuiter des por t e-fusibles.

Eviter de mouiller l' in st rument lors de son nettoyage. Les symboles suivants se trouvent sur l'instrument, ainsi que dans ce m anuel.

ATTENTION - se référer à la docum entation ci-jointe; toute utilisation

Courant alternatif (c.a. )

Tension d'alimentation secteur

La tension dalimentation de l'instrument est indiquée à l'arr ièr e. S' il est néces sair e de la m odifier de 230V à 115V ou vice-versa, procéder comme suit :

1. Débrancher l'instrument du secteur d' alimentat ion.

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 châss is et libérer la carte.

4. Changer les liaisons zéro ohm appropriées à côté du transf ormateur de la carte :

LK4 uniquement pour le fonctionnement à 230V LK3 et LK5 uniquement pour le fonct ionnement à 115V Noter que si le changement de tension de fonctionnement s'accompagne d'un

changement de fréq uence de la t ension, le r ej et du mode commun optimum de la tension du secteur peut être réalisé en définissant la sélect ion inter ne 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 s ous le m odule oscillateur de la carte de circuit principale. Sans liaison de court-circuit sur les broches, la fréquence est f ixée 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 êt r e recalibré à la nouvelle fréquence (le calibrage simultané à 100Hz et 120Hz est impossible).

Installation

5. Remonter la carte sur le châssis en s'assur ant que toutes les connexions (particulièrement la terre) sont rétablies et r em ont er le couvercle supér ieur.

6. Pour satisfaire aux exigences de sécurité, la tension d'alimentat ion sect eur indiquée à l'arrière de l'instrument doit êtr e modifiée pour indiquer la nouvelle tension opérationnelle.

7. Changer le fusible afin qu'il cor r esponde 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 -c irc uitag e des por te-fusibles est strictement interdit.

Cordon d'alimentation

Branchez cet instrument sur l’alimentation secteur en utilisant le câble d’alimentation fourni. Si la prise murale requiert l’utilisation d’un câble d’alimentation différent, un c âble appr opr ié et approuvé, qui possède une fiche correspondante à la prise m ur ale et un connec t eur d’inst r um ent IEC60320 C13, doit être utilisé. Pour vérifier la tension nominale du câble d’alimentation en fonction de la prise secteur, consultez les informations de puissance nominale sur l’équipement ou dans Caractérstiques.

AVERTISSEMENT ! CET INSTRUMENT DOIT ETRE RELIE A LA TERRE

Toute inter r uption du conducteur de terre secteur à l'intérieur ou à l' extér ieur de l' inst r ument rendra l'instrument dangereux. Toute interruption intentionnelle est absolument int er dit e.

Broche

Nom

Description

DCD

Reliée aux broches 4 et 6

TXD

Données transmises depuis l'instrument

RXD

Données reçues par l'instrument

DTR

Reliée aux broches 1 et 6

GND

Terre

DSR

Reliée aux broches 1 et 4

RTS

Reliée à la broche 8

CTS

Reliée à la broche 7

–

Aucune connexion interne

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 adaptat eur s fournis, lesquels sont eux-mêmes branchés aux connecteurs Kelvin. Les deux form es de c onnexion permettent le contact véritable à quatre bornes du com posant, pour garantir la mesure précise des composants de faible impédance.

Les fils des composants à sorties radiales peuvent être insérés dir ectement 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

Connexions distantes

Un gabarit de test à distance peut être connect é 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 f ois l'un de l'autre et aussi de l'écran du gabarit de test.

Les câbles jusqu'à un mètre de longueur s ont peu sus ceptibles de poser des problèmes, mais les câbles reliés à un gabarit externe doivent être aussi courts que possible et la pr écision 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.

RS232

Connecteur D à 9 broches pour contrôle à distance par ordinateur individuel :

Relier ce connecteur à un PC à l'aide d'un câble dont les broches 2, 3 et 5 sont câblées ent r e 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.

Cette section présente l'utilisation générale de l' inst r um ent. 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'inter r upt eur 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 q u' un c om posant lui est connecté, il le détecte automatiq uem ent et le m es ur e.

Pour couper entièrement l'instrument du sec t eur, débrancher le cordon d'alimentation à l'ar rière de l'instrument ; s'assurer que la déconnexion est facilement accessible. Débrancher l'instrum ent du secteur lorsqu'il est inutilisé.

Affichage

Fonctionnement

En utilisation normale, l'instrument aff iche le paramèt r e m ajeur (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 effect ué : pour ce faire, maintenir enf oncée 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'im pédance 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 ég alem ent , le fait de modifier la fréquenc e peut r amener le composant mesuré dans la plage de 0,1% de précision. Le f ait , par exemple, de mes ur er 680pF à la

fréquence Auto par défaut de 1kHz fait clignoter à la f ois l' indicat eur d' unit é ( pF) et de fréquence ; chang er 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'autr es fonctions qui sont expliquées à la section Tri des composants.

Touches et indicateurs de mesure

Fréquence

Le fait d'appuyer sur la touche Freq (Fr équence) 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 m es ur e plus pr écise du c om posant du type et de la valeur en cours.

Mode

Cette touche sélectionne le mode circuit série ou circuit parallèle équivalent à aff icher. Voir la section Principes de mesure. Si l'un des voyants clignote, il indique que l'autr e m ode de fonctionnement convient mieux au composant du type et de la valeur en cours de mesur e. 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 tens ions de polarisat ion jusqu’à 50 V CC peuvent être appliquées de manière externe : consulter la section Polarisation externe du chapit r e Principes de m es ur e.

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 êtr e ainsi éliminée. Le facteur de correction est perdu lorsque le pont est éteint. La fonction Zero C ne peut être utilisée que lorsqu'une c apacité est mesurée ; si une autre f onc t ion 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 paramèt r e majeur à gauche et le paramètre mineur à droite.

Auto

En mode Auto, l'instrument détecte automatiquement si le composant en cour s de m esure est une résistance, une capacité ou une inductance, et règle l'instrument pour afficher les paramètres de test du composant autom at iquement. Il convient de noter que les composants "imparfaits" tels que les inductances à résistance élevée en série peuvent être détect és 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 modif iée ( en appuyant sur la touche Freq) mais la sélection de mode Series/Parallel est maint enue 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 m ode Auto en sélectionnant la fonction appropriée (R+Q, L+ Q , etc.) ; le mode peut alors être m odifié à l'aide de la touche Mode.

Range Hold

Cette fonction maintient la gam m e de m es ur e en cours d'utilisation lorsque la touche est enfoncée. Ceci désactive le changement de g am me automatique et minimise le temps d'établissement entre mesures de composants d'une valeur similaire.

Il convient de noter que la gamme de la mesure de la t ension et du cour ant du composant sous test se définit manuellement, pour une précision et une résolution optimales ; le processeur détermine alors l'incertitude de mesure et fixe une résolution d'affichage appropriée. La f onct ion Range Hold (maintien de la gamme) f ixe toutes c es gammes. Si un composant d'une valeur très différente est mesuré et cause le dépassement de l' une quelconque de ces gammes, l'écran affiche

affichage exact.

or (hors gamme) et la fonction Range Hold doit être alors désactivée pour obtenir un

Touches de tri, de sauvegarde et de rappel

Les touches utilisées pour configurer le t r i et l'établissement de casiers de mémoire, pour sauvegarder et rappeler des config ur at ions, sont décrites à la section Tri des composants.

Lpj

LpRpj

jRsZs

LpQRp

jRsZs

−=

RpCpj

RpCp

RsCsD

CpD

Cs )

(

où

ω =

2πf

Modèles de circuits

Résistances, capacités et inductances peuvent tous être représentés à une certaine fréquence par un simple circuit série ou parallèle équivalent. Il convient de noter qu'il s'agit d' un simple circuit équivalent qui, en tant que tel, ne r epr ésent e qu'une plage de fréquences limitée. Les effets d'une vaste plage de fréquences sont abordés plus avant.

Les modèles utilisés par le LCR400 sont les suivants :

Principes de mesure

(D également : tg δ)

Résistances

Toutes les r ésistances ont des im pédanc es parasitaires, à la fois au niveau inductance et capacité et les effets des deux combinés. Heureusement, en conditions norm ales d' utilisation, ces effets parasitaires sont très faibles comparés à la résistance.

Le LCR 400 permet d'évaluer les composants série et parallèle des résistances à 100Hz, 1kHz et 10kHz.

Certains types de résistances présentent des effets parasitaires plus marqués que d'autres. Les résistances bobinées, à moins qu'elles ne soient spécialement bobinées, pr ésentent une inductance plus élevée que leurs équivalents à couche de carbone ou de métal. Même les résistances à couche de carbone présentent une inductance du fait de l' inductance des fils et de la coupe en spirale utilisée pour finir la résistance. Une capacité existe toujours entre les connexions d'extrémités : sur les résistances à f ilm m étallique, elle se sit ue t ypiquem ent autour de 0,25pF. Ceci ne devient important q ue s ur les r ésistances de valeur élevée ou/et aux hautes fréquences. Les résistances à enroulem ent bifilaire peuvent présenter une faible inductance, mais la proximité de l'enroulement peut induire une capacité importante répartie le long de la résistance. Pour prévoir la performance d'un t el com pos ant à de haut es fréquences, un circuit

équivalent plus complexe que le simple circuit série ou parallèle à deux composants abordés dans ce manuel est requis. En pratique, la solut ion consist e à s élect ionner des t ypes de composants qui correspondent à la plage de fréquence de l'application.

Pour la majorité des résistances où l'inductance et la capacité parasitaires sont minimes, les circuits série et parallèle donnent des résultats de mesure identiques.

Dans le cas des résistances pour lesquelles l'inductance est le parasite le plus important, le circuit série équivalent donne une valeur qui correspond à celle de la fiche technique du fabricant. Pour les composants de valeur élevée, la capacité peut commencer à être importante, et le circuit parallèle équivalent peut être plus approprié.

Normalement, R+Q devraient être sélectionnés pour les r ésistances, le Q d' une résistance étant généralement très bas, particulièrement aux basses fréquences de mesure utilisées. Toutefois, si les résistances série et parallèle à 10kHz diffèrent grandement de celles à 100Hz ou 1kHz, la valeur de Q est importante. Soit l'inductance ou la capacité de la résistance produit un effet. Le fait de sélectionner soit C+R soit L+Q quantifie la capacité ou l'inductance parasitaire.

Les résistances de faible valeur peuvent être mesurées à n'importe laquelle des trois fréquences de test du LCR400, mais les résistances d'une valeur plus élevée (>100kΩ) se mesurent mieux à 100Hz. L'instrument émet un avertissement si une m esur e s e t r ouve en dehors de la plag e de précision maximale, en faisant clignoter l'indicat eur d' unit és ; si la précision peut être améliorée en modifiant la fréquence de m es ur e, l' indicat eur de fréquence clignote aussi. Voir la section Affichage.

Capacités

Toutes les capacités prés ent ent une inductance et une résistance parasitaires en plus de leur capacité propre.

Les fils d'une capacité peuvent ajouter une inductance importance aux hautes fréquences. Les capacités bobinées à film métallique présentent une inductance parasitaire importante ; c'est pourquoi elles ne sont pas utilisées pour découpler de hautes fréquences. Certains types de capacités céramique peuvent fournir d'excellents outils de découplage : leur capacité est élevée et leur résistance et leur inductance série est faible, m ais les per t es peuvent êt r e im por tant es. Les capacités électrolytiques de valeur élevée peuvent présenter une inductance importante. Cette inductance peut même résonner avec la capacité aux fréquences de m es ur e du LCR400. Ceci a pour effet de montrer la capacité ou l'inductance négat ive d'une capacité donnée de haute valeur.

Les capacités présentent deux types principaux de résistance parasitaire. Elles présentent tout d'abord une résistance physique du diélectrique et des pertes diélectr iques ; ceci est normalement spécifié en termes de Dissipation Factor ‘D’ ou tangente de l'angle de perte et dépend de la fréquence. Ensuite, elles présent ent une r ésistance physique au niveau des fils et des connexions aux électrodes sur le diélectrique. La résistance des fils et de la connexion est généralement négligeable, mais à des niveaux électrolytiques élevés, utilisés pour le fitrage des alimentations, elle peut être très importante. La r ésistance sér ie de t els com pos ants est souvent un paramètre spécifié par le fabricant.

Pour la plupart des capacités autres que les électrolytiques à valeur élevée, le circuit parallèle équivalent fournit la capacité qui correspond à la f iche technique du fabricant. Pour les capacités à faible niveau de perte, les capacités série et parallèle sont identiques.

Les capacités électrolytiques sont sensibles à la polarité et leur connexion à l'instrument doit faire l'objet d'une attention particulière, la polarisat ion doit êt r e appliquée. Pour les électrolytiques de très haute valeur, pour lesquelles le fabricant spécifie Equivalent Series Resistance (ESR) (résistance en série équivalente ), c'est le circuit série équivalent qui doit être utilisé.

Le LCR 400 fournit le moyen de rechercher les pertes de capacités soit en t ermes de facteur de dissipation (C+D) soit en termes de résistance en série équivalente ou résistance en parallèle effective (C+R) .

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