Hameg HM8118 User Manual
HM8118
Programmable
LCR-Bridge
User Manual
38
General information concerning the CE marking
General information
concerning the
CE marking
General remarks regarding the CE marking
Hameg measuring instruments comply with the EMI
norms. Our tests for conformity are based upon the relevant norms. Whenever different maximum limits are optional Hameg will select the most stringent ones. As regards
emissions class 1B limits for small business will be applied. As regards susceptibility the limits for industrial environments will be applied. All connecting cables will inuence emissions as well as susceptability considerably. The
cables used will differ substantially depending on the application. During practical operation the following guidelines should be absolutely observed in order to minimize
emi:
1. Data connections
Measuring instruments may only be connected to external
associated equipment (printers, computers etc.) by using
well shielded cables. Unless shorter lengths are prescribed a maximum length of 3m must not be exceeded for
all data interconnections (input, output, signals, control).
In case an instrument interface would allow connecting
several cables only one may be connected. In general,
data connections should be made using double-shielded
cables. For IEEE-bus purposes the double screened cable
HZ72 from HAMEG is suitable.
2. Signal connections
In general, all connections between a measuring instrument and the device under test should be made as short
as possible. Unless a shorter length is prescribed a maximum length of 1m must not be exceeded, also, such connections must not leave the premises. All signal connections must be shielded (e.g. coax such as RG58/U). With
signal generators double-shielded cables are mandatory. It is especially important to establish good ground
connections.
3. External inuences
In the vicinity of strong magnetic or/and electric elds even
a careful measuring set-up may not be sufcient to gu-
ard against the intrusion of undesired signals. This will not
cause destruction or malfunction of Hameg instruments,
however, small deviations from the guaranteed specications may occur under such conditions.
HAMEG Instruments GmbH
DECLARATION OF CONFORMITY
HAMEG Instruments GmbH
Industriestraße 6 · D-63533 Mainhausen
The HAMEG Instruments GmbH herewith declares conformity of the
product:
Product name:
Programmable LCR-Bridge
Type: HM8118
with: HO820
Option: HO880
complies with the provisions of the Directive of the Council of the
European Union on the approximation of the laws of the Member States
❙ relating to electrical equipment for use within dened voltage limits
(2006/95/EC) [LVD]
❙ relating to electromagnetic compatibility (2004/108/EC) [EMCD]
❙ relating to restriction of the use of hazardous substances in
electrical and electronic equipment (2011/65/EC) [RoHS].
Conformity with LVD and EMCD is proven by compliance with the
following standards:
EN 61010-1: 04/2015
EN 61326-1: 07/2013
EN 55011: 11/2 014
EN 61000-4-2: 12/2009
EN 61000-4-3: 04/2011
EN 61000-4-4: 04/2013
EN 61000-4-5: 03/2015
EN 61000-4-6: 08/2014
EN 61000-4-11: 02/2005
EN 61000-6-3: 11/2012
For the assessment of electromagnetic compatibility, the limits of
radio interference for Class B equipment as well as the immunity to
interference for operation in industry have been used as a basis.
Date:
8.6.2015
Signature:
Holger Asmussen
General Manager
39
Content
1 Important Notes ....................... 40
1.1 Symb o l s ..................................40
1.2 Unpacking .................................40
1.3 Setting Up the Instrument ....................40
1.4 Safet y ....................................40
1.5 Intended Operation ..........................40
1.6 Ambient Conditions .........................41
1.7 Warranty and Repair .........................41
1.8 Maintenance ...............................41
1.9 Line fuse ..................................41
1.10 Power switch ..............................41
1.11 Batteries and Rechargeable Batteries/Cells .......41
1.12 Product Disposal ............................42
2 Description of the Operating Elements .....43
3 Introduction ..........................45
3.1 Requirements ..............................45
3.2 Measurement of a capacitor ..................45
3.3 Measurement of an inductor ..................45
4 First-Time Operation .................... 46
4.1 Connecting the instrument ....................46
4.2 Turning on the instrument ....................46
3.4 Measurement of a resistor ....................46
4.3 Line frequency .............................47
4.4 Measurement Principle .......................47
4.5 Measurement Accuracy ......................48
5 Setting of Parameters ..................49
5.1 Selecting Values /Parameters ..................49
6 Measurement Value Display. . . . . . . . . . . . . . 50
6.1 Relative Measurement Value Deviation ∆ %
(#, %)
.....................................50
6.2 Absolute Measurement Value Deviation ∆ ABS (#) .50
5.2 Selecting the Measurement Function ...........50
6.3 Reference Value (REF_M, REF_S) ...............51
6.4 Selecting the Measurement Range .............51
6.5 Circuit Type ................................52
7 Instrument Functions ................... 52
7.1 SETUP Menu. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .52
7.1.1 Measurement Frequency FRQ
.................52
7.1.2 Voltage LEV ...............................53
7.1.3 Preload/ Bias Current BIAS ...................53
7.1.4 Measurement Range RNG ....................54
7.1.5 Measurement Speed SPD ....................54
7.1.6 Triggering TRIG ............................55
7.1.7 DELAY Function ............................55
7.1.8 Average Value AVG ..........................55
7.1.9 Display of Test Signal Level Vm (Measurement Voltage) / Im (Measurement Current):
..............55
7.1.10 Guarding GUARD ...........................55
7.1.11 Dev i a tion DEV_ M ...........................56
7.1.12 Ref erence REF_M ...........................56
7.1.13 Dev i a tion DEV_ S ............................56
7.1.14 Ref erence REF_S ...........................56
7.1.15 CONSTANT VOLTAGE CST V ..................56
7.2 CORR Menu ...............................57
7.3 Menu Function SYST ........................58
7.4 Saving / Loading of Settings ..................59
7.5 Factory Settings ............................59
8 Measuring Equipment ..................60
8.1 4-Wire Test Adapter HZ181 (Including Short Circuit
Board) ....................................60
8.2 Kelvin-Test Lead HZ184 ......................61
8.3 4-wire Transformer Test Lead HZ186 ............61
8.4 4-Wire SMD Test Adapter HZ188 ...............63
8.5 Sorting Components with Option HO118 Binning
Interface
..................................64
9 Remote Control .......................66
8.1 RS -232 ....................................66
8.2 USB / VCP .................................67
8.3 IEEE-488 (GPIB) ............................67
10 Command Reference ...................68
10
.1 Setting Up the Command Structure ............68
10
.2 Supported Command and Data Formats .........68
10
.3 Command List Binning Interface ...............71
11 Technical Data ........................72
Content
40
Important Notes
1 Important Notes
1.1 Symbols
(1) (2) (3)
Symbol 1: Caution, general danger zone –
Refer to product documentation
Symbol 2: Risk of electric shock
Symbol 3: Ground terminal
1.2 Unpacking
While unpacking, check the package contents for completeness (measuring instrument, power cable, product
CD, possibly optional accessories). After unpacking, check
the instrument for mechanical damage occurred during
transport and for loose parts inside. In case of transport
damage, please inform the supplier immediately. The instrument must not be operated in this case.
1.3 Setting Up the Instrument
Two positions are possible: .
According to Fig. 1 the front feet are folded down and are
used to lift the instrument so its front points slightly upward (approx. 10 degrees). If the feet are not used (Fig. 2)
the instrument can be stacked safely with many other HAMEG
instruments. In case several instruments are stakked (Fig. 3) the feet rest in the recesses of the instrument
below so the instruments can not be inadvertently moved. Please do not stack more than 3 instruments. A higher stack will become unstable, also heat dissipation may
be impaired.
Fig. 1
Fig. 2
Fig. 3
1.4 Safety
This instrument was built in compliance with VDE 0411
part 1, safety regulations for electrical measuring instruments, control units and Iaboratory equipment. It has
been tested and shipped from the plant in safe condition.
It is in compliance with the regulations of the European
standard EN 61010-1 and the international standard IEC
61010-1. To maintain this condition and to ensure safe operation, the user must observe all instructions and warnings given in this operating manual. Casing, chassis and
all measuring ports are connected to a protective earth
conductor. The instrument is designed in compliance with
the regulations of protection class 0.
For safety reasons, the instrument may only be operated
with authorized safety sockets. The power cord must be
plugged in before signal circuits may be connected. Never
use the product if the power cable is damaged. Check regularly if the power cables are in perfect condition. Choose
suitable protective measures and installation types to ensure that the power cord cannot be damaged and that no
harm is caused by tripping hazards or from electric shock,
for instance.
If it is assumed that a safe operation is no longer possible,
the instrument must be shut down and secured against
any unintended operation.
Safe operation can no longer be assumed:
❙ If the measuring instrument shows visible damage
❙ If the measuring instrument no longer functions properly
❙ After an extended period of storage under unfavorable
conditions (e.g. outdoors or in damp rooms)
❙ After rough handling during transport (e.g. packaging that
does not meet the minimum requirements by post ofce,
railway or forwarding agency).
In case of doubt the power connector should be checked
according to DIN VDE 0100/610:
❙ Only qualied personnel may open the instrument
❙ Prior to opening the instrument must be disconnected
from the line and all other inputs/outputs.
1.5 Intended Operation
The measuring instrument is intended only for use by personnel familiar with the potential risks of measuring electrical quantities. For safety reasons, the measuring instrument may only be connected to properly installed safety
socket outlets. Separating the grounds is prohibited. The
power plug must be inserted before signal circuits may be
connected. The product may be operated only under the
operating conditions and in the positions specied by the
manufacturer, without the product’s ventilation being ob-
structed. If the manufacturer’s specications are not observed, this can result in electric shock, re and/or serious
personal injury, and in some cases, death. Applicable local
It is prohibited to disconnect the earthed protective
connection inside or outside the instrument!
41
Important Notes
or national safety regulations and rules for the prevention
of accidents must be observed in all work performed.
The measuring instrument is designed for use in the following sectors: Industry, residential, business and commercial areas and small businesses.
The measuring instrument is designed for indoor use only.
Before each measurement, you need to verify at a known
source if the measuring instrument functions properly.
1.6 Ambient Conditions
The allowed operating temperature ranges from +5°C to
+40 °C (pollution category 2). The maximum relative hu-
midity (without condensation) is at 80%. During storage
and transport, the temperature must be between -20 °C
and +70 °C. In case of condensation during transportation
or storage, the instrument will require approximately two
hours to dry and reach the appropriate temperature prior
to operation. The measuring instrument is designed for
use in a clean and dry indoor environment. Do not operate
with high dust and humidity levels, if danger of explosion
exists or with aggressive chemical agents. Any operating
position may be used; however adequate air circulation
must be maintained. For continuous operation, a horizontal
or inclined position (integrated stand) is preferable.
The maximum operating altitude for the instrument is
2000 m. Specications with tolerance data apply after a
warm up period of at least 30 minutes at a temperature of
23 °C (tolerance ±2 °C). Specications without tolerance
data are average values.
1.7 Warranty and Repair
Our instruments are subject to strict quality controls. Prior
to leaving the manufacturing site, each instrument undergoes a 10-hour burn-in test. This is followed by extensive
functional quality testing to examine all operating modes
and to guarantee compliance with the specied technical
data. The testing is performed with testing equipment that
is calibrated to national standards. The statutory warranty
provisions shall be governed by the laws of the country
in which the product was purchased. In case of any complaints, please contact your supplier.
Use the measuring instrument only with original HAMEG measuring equipment, measuring cables and power cord. Never use inadequately measured power cords. Before each measurement,
measuring cables must be inspected for damage and replaced if
necessary. Damaged or worn components can damage the instrument or cause injury.
To disconnect from the mains, the low-heat device socket on the
back panel has to be unplugged.
The product may only be opened by authorized and
qualied personnel. Prior to working on the product or
before the product is opened, it must be disconnected
from the AC supply network. Otherwise, personnel will
be exposed to the risk of an electric shock.
Any adjustments, replacements of parts, maintenance and
repair may be carried out only by authorized technical personnel. Only original parts may be used for replacing parts
relevant to safety (e.g. power switches, power transformers, fuses). A safety test must always be performed after
parts relevant to safety have been replaced (visual inspection, PE conductor test, insulation resistance measurement,
leakage current measurement, functional test). This helps
ensure the continued safety of the product.
1.8 Maintenance
The display may only be cleaned with water or an
appropriate glass cleaner (not with alcohol or other
cleaning agents). Follow this step by rubbing the display
down with a dry, clean and lint-free cloth. Do not allow
cleaning uid to enter the instrument. The use of other
cleaning agents may damage the labeling or plastic and
lacquered surfaces.
1.9 Line fuse
The instrument has 2 internal line fuses: T 0.8 A. In case of
a blown fuse the instrument has to be sent in for repair. A
change of the line fuse by the customer is not permitted.
1.10 Power switch
The instrument has a wide range power supply from 105
V to 253 V, 50 Hz or 60 Hz ±10 %. There is hence no line
voltage selector.
Fuse type:
Size 5 x 20 mm; 250V~, C; IEC 127, Bl. III; DIN 41 662 (possibly DIN 41 571, Bl. 3). Slow-blow (T) 0,8A.
1.11 Batteries and Rechargeable Batteries/Cells
1. Cells must not be disassembled, opened or crushed.
2. Cells and batteries may not be exposed to heat or re.
Storage in direct sunlight must be avoided. Keep cells
and batteries clean and dry. Clean soiled connectors
using a dry, clean cloth.
Clean the outer case of the measuring instrument at regular intervals, using a soft, lint-free dust cloth.
Before cleaning the measuring instrument, please make sure that
it has been switched off and disconnected from all power supplies (e.g. AC supply network).
No parts of the instruments may be cleaned with chemical cleaning agents (such as alcohol, acetone or cellulose thinner)!
If the information regarding batteries and rechargeable batteries/
cells is not observed either at all or to the extent necessary, product users may be exposed to the risk of explosions, re and/or serious personal injury, and, in some cases, death. Batteries and rechargeable batteries with alkaline electrolytes (e.g. lithium cells)
must be handled in accordance with the EN 62133 standard.
42
Important Notes
3. Cells or batteries must not be short-circuited. Cells or
batteries must not be stored in a box or in a drawer
where they can short-circuit each other, or where they
can be short-circuited by other conductive materials.
Cells and batteries must not be removed from their
original packaging until they are ready to be used.
4. Keep cells and batteries out of reach of children. Seek
medical assistance immediately if a cell or battery was
swallowed.
5. Cells and batteries must not be exposed to any me-
chanical shocks that are stronger than permitted.
6. If a cell develops a leak, the uid must not be allowed
to come into contact with the skin or eyes. If contact
occurs, wash the affected area with plenty of water
and seek medical assistance.
7. Improperly replacing or charging cells or batteries can
cause explosions. Replace cells or batteries only with
the matching type in order to ensure the safety of the
product.
8. Cells and batteries must be recycled and kept separate
from residual waste. Cells and batteries must be recycled and kept separate from residual waste. Rechargeable batteries and normal batteries that contain lead,
mercury or cadmium are hazardous waste. Observe
the national regulations regarding waste disposal and
recycling.
1.12 Product Disposal
The Electrical and Electronic Equipment Act implements
the following EG directives:
❙ 2002/96/EG (WEEE) for electrical and electronic
equipment waste and
❙ 2002/95/EG to restrict the use of certain hazardous
substances iin electronic equipment (RoHS directive).
❙
Once its lifetime has ended, this product should be disposed of separately from your household waste. The disposal at municipal collection sites for electronic equipment is also not permitted. As mandated for all manufacturers by the Electrical and Electronic Equipment Act (ElektroG), ROHDE & SCHWARZ assumes full responsibility for
the ecological disposal or the recycling at the end-of-life of
their products.
Please contact your local service partner to dispose of the
product.
Fig. 1.4: Product labeling in accordance
with EN 50419
43
Description of the Operating Elements
Fig. 2.1: Front panel of HM8118
2 Description of
the Operating
Elements
Front panel of H M 8118
1
POWER – Turning on/off the instrument
2
DISPLAY (LCD) – Display of measurement results and
units, ranges, frequencies, level, equivalent circuit,
functions and parameters
MENU
3
SELECT – Opening the submenus SETUP, CORR, SYST
and BIN (only with installed Binning Interface HO118)
4
ENTER – Conrmation of input values
5
ESC – Cancel the menu function
6
Rotary knob (Knob/Pushbutton) – Selection of func-
tions and parameters
7
Arrow buttons – Pushbuttons for parameter
selection
SET
8
FREQ – Setting of the test signal frequency with rotary
knob 6 or arrow buttons
7
9
LEVEL – Setting of the test signal level with rotary knob
6
and cursor position with arrow buttons
7
10
BIAS – Setting of the bias voltage or current with ro-
tary knob
6
and cursor position with arrow buttons
7
ZERO
11
OPEN – Activating the OPEN calibration
12
SHORT – Activating the SHORT calibration
13
LOAD – Activating the LOAD calibration
MODE
14
AUTO – Activating the automatic selection of equiva-
lent circuit
15
SER – Activating the series equivalent circuit
16
PAR – Activating the parallel equivalent circuit
RANGE
17
AUTO/HOLD – Activating the automatic measurement
range (LED lights up) or the range HOLD function
18
UP – Range up
19
DOWN – Range down
Connectors
20
L CUR (BNC socket) – Low Current; signal output for
series measurements (signal generator)
21
L POT (BNC socket) – Low Potential; signal input for pa-
rallel measurement (voltage measurements)
22
H POT (BNC socket) – High Potential; signal input / out-
put for parallel measurements (measurement bridge)
23
H CUR (BNC socket) – High Current; signal input for se-
ries measurements (current measurements)
Instrument functions
24
BIAS MODE/ESC – Activating of internal / external bias
voltage resp. cancelling the editing mode (ESC)
25
TRIG MODE/ENTER – Changing the trigger mode resp.
conrming an input value
26
BIAS / – Activating the bias voltage resp. erasing
the last character of an numeric input
27
TRIG / UNIT – Single trigger in manual trigger mode
resp. selection of a parameter unit
28
AUTO / 6 – Activating the automatic measurement
function resp. entering numeric value 6
29
M / – – Selection of the measurement function „Mutual
Inductance“ resp. parameter input of the character „-“.
30
R-Q / 5 – Selection of the measurement function ‘Resis-
tance‘ R und ‘Quality factor‘ Q resp. entering numeric
value 5
1 2 4 3
5
6 7 9 8 10
12 11 13
15 14 16
18 17 19
22 21
20
24
43
232526
27282930313233343536373839424041
44
Description of the Operating Elements
Fig. 2.2: Back panel of HM8118
47 48
45
4446
49
31
N-Θ / . – Selection of the measurement function ‘Turns
ratio‘ N and ‘Phase angle‘ Θ resp. parameter input of
the character “. “
32
C-R / 4 – Selection of the measurement function ‘Ca-
pacitance‘ C and ‘Resistance‘ R resp. entering numeric
value 4
33
G-B / 0 (Pushbutton)
Selection of the measurement function ‘Conductance‘
G and ‘Susceptance‘ B resp. entering numeric value 0
34
C-D / 3 – Selection of the measurement function ‘Capa-
citance‘ C and ‘Dissipation factor‘ D resp. entering numeric value 3
35
R-X / 9 – Selection of the measurement function ‘Resis-
tance‘ R and ‘Reactance‘ X resp. entering numeric value 9
36
L-R / 2 – Selection of the measurement function ‘Induc-
tance‘ L and ‘Resistance‘ R resp. entering numeric value 2
37
Y-Θ / 8 – Selection of the measurement function ‘Ad-
mittance‘ Y and ‘Phase angle‘ Θ resp. entering numeric
value 8
38
L-Q / 1 – Selection of the measurement function ‘Induc-
tance‘ and ‘Quality factor‘ Q resp. entering numeric value 1
39
Z-Θ / 7 – Selection of the measurement function ‘Im-
pedance‘ Z and ‘Phase angle‘ Θ resp. entering numeric
value 7
40
DISPLAY MODE – Toggling the display of measurement
values with / without parameters
41
RECALL / STORE – Loading/storing of instrument
settings
42
REMOTE / LOCAL – Toggling between front panel (LO-
CAL) or remote operation (LED lights up); if local lockout was activated, the instrument can not be operated
from the front panel.
43
Ground (4 mm socket) – Ground connector ( ). The so-
cket is directly connected to the mains safety ground!
Back panel of HM8118
44
TRIG. INPUT (BNC socket) –
Trigger input for external trigger
45
BIAS FUSE (Fuse holder) –
Fuse for external voltage input ext. BIAS
46
EXT. BIAS (4 mm safety sockets) –
External bias input (+, –)
47
INTERFACE – HO820 Dual Interface USB/RS-232 (gal-
vanically isolated) is provided as standard
48
BINNING INTERFACE (25 pin D-Sub socket) –
Output to control external binning sorters for components (option HO118)
49
POWER INPUT (Power Cord Receptacle)
45
Introduction
3 Introduction
3.1 Requirements
❙ HAMEG HM8118 LCR measuring bridge with rmware
from 1.37 upwards.
❙ HZ184 Kelvin measurement cables
❙ 1 x HAMEG 1,000 µF capacitor (not contained in
shipment)
❙ 1 x HAMEG 280 µH inductor (not contained in shipment)
❙ 1 x HAMEG 100 kΩ resistor (not contained in shipment).
First connect the HZ184 cables supplied to the HM8118.
The two plugs of the black cable are connected to the terminals LCUR and LPOT, the plugs of the red cable to the
terminals HCUR and HPOT.
After turning the instrument on, the rst steps are the open
circuit and the short circuit calibration procedures at the
preselected frequency of 1.0 kHz because the measurement cables HZ184, in conjunction with the terminals, due
to their design, show a stray capacity, a residual inductance and a residual resistance which impair the accuracy
of the measurement results. In order to minimize these in-
uences, the compensation of impedance measurement
errors caused by adapters and cables is necessary.
For the open circuit calibration, position the two clips apart
from each other. For the short circuit calibration connect
both clips as shown in Fig. 3.1.
Push the button MENU/SELECT
3
and then the button
C-D
34
in order to enter the CORR menu. Select the menu
item MODE and use the knob
6
to change the menu entry
from SGL to ALL in order to automatically perform the calibration at all 69 frequency steps provided. Leave the menu
by pushing the button MENU/ESC
5
.
The following components are only intended to be used as an example for a quick introduction to the instrument.
Fig. 3.1: Short circuit calibration with HZ184.
The mode SGL is used to only calibrate at the presently selected
frequency; this procedure takes just a few seconds and is destined for measurements in one or a few frequency ranges only.
Now start the open and short circuit calibrations by
pushing the buttons ZERO/OPEN
11
resp. ZERO/SHORT
12
. The instrument will now determine correction factors
at all 69 frequency steps valid for the presently connected
measurement cables and store them until the instrument is
switched off. This procedure will last appr. 2 minutes.
3.2 Measurement of a capacitor
Now connect the capacitor to the terminals of the HZ184.
Please observe the polarity of the capacitor and connect
the black terminal to the negative terminal of the capacitor,
marked with a – (minus).
As the instrument is set to automatic mode, the measurement function will be automatically switched to function
no. 3 (C-D). Because the measuring frequency of 1.0 kHz
was preselected, the capacitor will not be measured in its
regular operating mode, so the value displayed of appr.
900 µF will not equal the specied value of 1,000 µF.
Change the measuring frequency to 50 Hz by pushing the
button SET/FREQ
8
and turning the knob until 50 Hz are
shown on the display. Now the value displayed will change
to appr.1,000 µF depending on its tolerance. The dissipation factor „D“ will be very low at this setting.
The smaller the loss angle, the more the real world components will come close to the ideal. An ideal inductor has
a loss angle of zero degrees. An ideal capacitor also has
a loss angle of zero degrees. An ideal electrical resistor,
however, has a loss angle of 90 degrees, it has no capacitive or inductive components.
3.3 Measurement of an inductor
Before you connect the choke, increase the measuring frequency by one decade to 500 Hz by pushing the arrow
button 7 above the knob. Disconnect the capacitor and
connect the choke to the terminals of the HZ184.
The instrument will now automatically switch to the function no. 1 (L-Q) and the inductance of the choke will be dis-
|Z| = 1000
Ω
Q = 500
D = 0,002
Q = 500
D = 0,002
D = 500
Q = 0,002
D = Q = 1
D = Q = 1
R
jX
D = 500
Q = 0,002
Fig. 3.2: HM8118 measurement principle, left: schematic, right: detailled
presentation.
Imaginary
Axis
below -- 45° = C
above 45° = L
Real
Axis
phase angle
46
Introduction
played. The value should be appr. 280 µH. As shown in Fig.
3.2, the phase angle of an inductor must be in the range
of + 45 to 90°. In order to prove this, leave the automatic
mode by pushing the button „Z-Θ
39
. The phase angle displayed will be appr. +70° and depends on the measuring
frequency set.
For comparison: the phase angle of the capacitor measured before is appr. -87° at 50 Hz.
3.4 Measurement of a resistor
Disconnect the choke and connect the 100 kΩ resistor supplied. As the instrument was previously set manually to the
function Z-Θ, the value of its impedance can be directly
read (appr. 100 kΩ). As decribed on the page before, an
ideal resistor has no capacitive or inductive components.
Hence the phase resp. loss angle of the component connected is close to zero degrees.
The HM8118, upon connection of the resistor, automatically changed the internal equivalent circuit from series
connection SER to parallel connection PAR (LED pushbuttons
15
and 16). If the automatic selection of the equivalent
circuit was chosen (pushbutton AUTO
14
), the LCR measuring bridge will automatically select the equivalent circuit
which, depending on the component connected, is best
suited to yield a precise measurement result. The equivalent circuit represents the measurement circuit. Usually,
components with a low impedance (capacitors, chokes)
will be measured using the series connection equivalent
circuit while components with a high impedance (e.g. resistors) will be measured using the parallel
equivalent circuit.
4 First-Time Ope-
ration
4.1 Connecting the instrument
Prior to connecting the instrument to the mains, check
whether the mains voltage conforms to the mains voltage
range specied on the rear panel. This instrument has a
wide-range power supply and hence requires no manual
setting of the mains voltage.
The fuse holder of the BIAS FUSE
45
, i.e. the external BIAS
input, is accessible on the rear panel. Prior to exchanging a
fuse the instrument must be disconnected from the mains.
Then the fuse holder may be removed with a suitable
screw driver, using the slot provided. Afterwards the fuse
can be removed from the holder and exchanged. The holder is spring-loaded and has to be pushed in and turned.
It is prohibited to use „repaired“ fuses or to short-circuit
the fuse. Any damages incurred by such manipulations will
void the warranty. The fuse may only be exchanged by this
type:
Fuse with ceramic body, lled with re extinguishing
material:
Size 6.3 x 32 mm; 400 VAC, C; IEC 127, Bl. III; DIN 41 662
(alternatively DIN 41 571, p. 3), (F) 0,5 A
4.2 Turning on the instrument
Prior to operating the instrument for the rst time, please be sure to observe the safety instructions mentioned
previously!
The LCR bridge is switched on by using the power switch
1
. Once all keys have briey been illuminated, the bridge
can be operated via keys and the knob on the front panel. If the keys and the display do not light up, either the
mains voltage is switched off or the internal input line fuses are defective. The current measurement results are
Fig. 4.1: Power Input
Fig. 4.2: Rear panel with fuse
47
First-Time Operation
shown in the right panel and the essential parameters in
the left panel of the display. The four BNC sockets located
on the front panel can be connected to the component to
be measured with the appropriate measuring accessories.
Additionally, it is also possible to connect the measuring
instrument via ground socket on the front panel
43
with
ground potential. The socket is suitable for a banana plug
with a 4 mm diameter.
If there are undened messages on the display or if the instrument fails to react to operation of its controls turn it
off, wait a minute and turn it on again in order to trigger a
reset operation. If the display remains unchanged or operation impossible, turn it off and take it to a qualied service point (see Safety Instructions).
4.3 Line frequency
Prior to rst measurements, the line frequency setting
must be set to the applied line frequency, 50 or 60 Hz. If
the line frequency is not set properly, depending on the
measurement range and the line frequency value, instabilities may occur e.g. on the display. In order to set the
line frequency press the SELECT button
3
, use the SYST
menu for accessing MAINS FRQ, use the knob
6
for se-
lecting the correct value.
4.4 Measurement Principle
The LCR meter HM8118 is not a traditional Wien, Maxwell
or Thomson measurement bridge. Rather, when connecting a test object, the impedance |Z| and the correspon-
ding phase angle Θ (phase between current and voltage)
are always determined (see g. 4.3). These measurement
values are frequency dependent and will be determined
by means of an AC test signal (which can be set manually
between 50mV and 1.5V). The test signal is induced in the
test item. This distinguishes a LCR bridge from a multimeter (DC measurement). Based on the measurement principle, the measured impedance is always essential. Based
on the impedance (X axis) and the phase angel (angle), the
instrument is able to determine the missing value of the
Y axis. This means that it is not the DC component that is
being measured but rather the AC value. The issued values
are calculated digitally. This measurement of impedance
and phase angle is subject to a certain measurement inaccuracy which will be described on the following pages.
In general, the HM8118 bridge can only determine the
ESR, ESC or ESL (= Equivalent Series Resistance / Capacity / Inductivity) according to the equivalent circuit dia-
The front panel ground connector and the ground contact of the
trigger input are directly connected to the mains safety ground
potential through the line cord. The outer contacts of the front
panel BNC connectors
20
– 23 (as well as the shields of any coaxial cables attached) are connected to the GUARD potential
which has no connection to the safety ground! No external voltages may be applied to the BNC connectors! The rear panel interfaces
47
and 48 are galvanically isolated (no connection to
ground)!
gram of the component and is primarily used to measure
individual components. If a circuit with multiple components is connected to the bridge, the instrument will always determine the ESR, ESC or ESL of the entire circuit
/ component group. This can potentially skew the measurement result. The connected component / circuit is assumed to be the „Black Box“. These values are available for
each component; however, please keep in mind that these
always describe the result of multiple, possibly overlapping
individual capacities, inductances and impedances. This
can easily cause some misunderstandings especially with
coils (magnetic eld, eddy currents, hysteresis, etc.)
Fig. 4.4 shows the link between capacity C
s
(or resistance
R
s
) and various test voltages that can be selected with the
bridge (0.2V
eff
to 1.5 V
eff
). As can be seen in the gure, the
measurement values of C
s
or Rs are highly dependent on
the selected test voltage. Point A shows the test point of
the instrument during the measurement of a single component, point B shows the test point during the measurement of a component group (in this case two capacities connected in parallel). In contrast to test point A, with
point B the bridge switches the measurement range due
to the impedance of the entire component group. As a result, the measurement results for point A and point B are
different.
The LCR bridge HM8118 is primarily intended to determine passive components. Therefore, it is not possible to determine test
objects which are externally supplied with power.
|Z| = 1000
Ω
Q = 500
D = 0,002
Q = 500
D = 0,002
D = 500
Q = 0,002
D = Q = 1
D = Q = 1
R
jX
D = 500
Q = 0,002
Imaginary
Axis
below -- 45° = C
above 45° = L
Real
Axis
phase angle
Q = Quality factor
D = Loss tangent
D = 1 / Q
Q = 1 / D = 1 / tan delta
(delta = Opposite angle of the phase angle)
Fig. 4.3: Measurement principle
Loading...