B&K Precision 891 User's Manual
Model: 891
300 kHz Bench LCR Meter
USER MANUAL
Safety Summary
The following safety precautions apply to both operating and maintenance
personnel and must be followed during all phases of operation, service, and
repair of this instrument.
Before applying power to this instrument:
Read and understand the safety and operational information in this
manual.
Apply all the listed safety precautions.
Verify that the voltage selector at the line power cord input is set to
the correct line voltage. Operating the instrument at an incorrect line
voltage will void the warranty.
Make all connections to the instrument before applying power.
Do not operate the instrument in ways not specified by this manual
or by B&K Precision.
Failure to comply with these precautions or with warnings elsewhere in this
manual violates the safety standards of design, manufacture, and intended
use of the instrument. B&K Precision assumes no liability for a customer’s
failure to comply with these requirements.
Category rating
The IEC 61010 standard defines safety category ratings that specify the
amount of electrical energy available and the voltage impulses that may occur
on electrical conductors associated with these category ratings. The category
rating is a Roman numeral of I, II, III, or IV. This rating is also accompanied by a
maximum voltage of the circuit to be tested, which defines the voltage
impulses expected and required insulation clearances. These categories are:
Category I (CAT I): Measurement instruments whose measurement inputs are
not intended to be connected to the mains supply. The voltages in the
environment are typically derived from a limited-energy transformer or a
i
battery.
Category II (CAT II): Measurement instruments whose measurement inputs
are meant to be connected to the mains supply at a standard wall outlet or
similar sources. Example measurement environments are portable tools and
household appliances.
Category III (CAT III): Measurement instruments whose measurement inputs
are meant to be connected to the mains installation of a building. Examples
are measurements inside a building's circuit breaker panel or the wiring of
permanently-installed motors.
Category IV (CAT IV): Measurement instruments whose measurement inputs
are meant to be connected to the primary power entering a building or other
outdoor wiring.
Do not use this instrument in an electrical environment with a higher
category rating than what is specified in this manual for this instrument.
You must ensure that each accessory you use with this instrument has a
category rating equal to or higher than the instrument's category rating to
maintain the instrument's category rating. Failure to do so will lower the
category rating of the measuring system.
Electrical Power
This instrument is intended to be powered from a CATEGORY II mains power
environment. The mains power should be 115 V RMS or 230 V RMS. Use only
the power cord supplied with the instrument and ensure it is appropriate for
your country of use.
ii
Ground the Instrument
To minimize shock hazard, the instrument chassis and cabinet must be
connected to an electrical safety ground. This instrument is grounded through
the ground conductor of the supplied, three-conductor AC line power cable.
The power cable must be plugged into an approved three-conductor
electrical outlet. The power jack and mating plug of the power cable meet IEC
safety standards.
Do not alter or defeat the ground connection. Without the safety ground
connection, all accessible conductive parts (including control knobs) may
provide an electric shock. Failure to use a properly-grounded approved outlet
and the recommended three-conductor AC line power cable may result in
injury or death.
Unless otherwise stated, a ground connection on the instrument's front or
rear panel is for a reference of potential only and is not to be used as a safety
ground.
Do not operate in an explosive or flammable atmosphere
Do not operate the instrument in the presence of flammable gases or vapors,
fumes, or finely-divided particulates.
iii
The instrument is designed to be used in office-type indoor environments. Do
not operate the instrument
In the presence of noxious, corrosive, or flammable fumes, gases,
vapors, chemicals, or finely-divided particulates.
In relative humidity conditions outside the instrument's
specifications.
In environments where there is a danger of any liquid being spilled
on the instrument or where any liquid can condense on the
instrument.
In air temperatures exceeding the specified operating temperatures.
In atmospheric pressures outside the specified altitude limits or
where the surrounding gas is not air.
In environments with restricted cooling air flow, even if the air
temperatures are within specifications.
In direct sunlight.
This instrument is intended to be used in an indoor pollution degree 2
environment. The operating temperature range is 0 °C to 40 °C and 20% to
80% relative humidity, with no condensation allowed.
Measurements made by this instrument may be outside specifications if the
instrument is used in non-office-type environments. Such environments may
include rapid temperature or humidity changes, sunlight, vibration and/or
mechanical shocks, acoustic noise, electrical noise, strong electric fields, or
strong magnetic fields.
Do not operate instrument if damaged
iv
If the instrument is damaged, appears to be damaged, or if any liquid,
chemical, or other material gets on or inside the instrument, remove the
instrument's power cord, remove the instrument from service, label it as not
to be operated, and return the instrument to B&K Precision for repair. Notify
B&K Precision of the nature of any contamination of the instrument.
Clean the instrument only as instructed
Do not clean the instrument, its switches, or its terminals with contact
cleaners, abrasives, lubricants, solvents, acids/bases, or other such chemicals.
Clean the instrument only with a clean dry lint-free cloth or as instructed in
this manual.
Not for critical applications
This instrument is not authorized for use in contact with the human body or
for use as a component in a life-support device or system.
Do not touch live circuits
Instrument covers must not be removed by operating personnel. Component
replacement and internal adjustments must be made by qualified servicetrained maintenance personnel who are aware of the hazards involved when
the instrument's covers and shields are removed. Under certain conditions,
even with the power cord removed, dangerous voltages may exist when the
covers are removed. To avoid injuries, always disconnect the power cord from
v
the instrument, disconnect all other connections (for example, test leads,
computer interface cables, etc.), discharge all circuits, and verify there are no
hazardous voltages present on any conductors by measurements with a
properly-operating voltage-sensing device before touching any internal parts.
Verify the voltage-sensing device is working properly before and after making
the measurements by testing with known-operating voltage sources and test
for both DC and AC voltages. Do not attempt any service or adjustment unless
another person capable of rendering first aid and resuscitation is present.
Do not insert any object into an instrument's ventilation openings or other
openings.
Hazardous voltages may be present in unexpected locations in circuitry being
tested when a fault condition in the circuit exists.
Fuse replacement
Fuse replacement must be done by qualified service-trained maintenance
personnel who are aware of the instrument's fuse requirements and safe
replacement procedures. Disconnect the instrument from the power line
before replacing fuses. Replace fuses only with new fuses of the fuse types,
voltage ratings, and current ratings specified in this manual or on the back of
the instrument. Failure to do so may damage the instrument, lead to a safety
hazard, or cause a fire. Failure to use the specified fuses will void the
warranty.
Servicing
Do not substitute parts that are not approved by B&K Precision or modify this
instrument. Return the instrument to B&K Precision for service and repair to
vi
ensure that safety and performance features are maintained.
Cooling fans
This instrument contains one or more cooling fans. For continued safe
operation of the instrument, the air inlet and exhaust openings for these fans
must not be blocked nor must accumulated dust or other debris be allowed
to reduce air flow. Maintain at least 25 mm clearance around the sides of the
instrument that contain air inlet and exhaust ports. If mounted in a rack,
position power devices in the rack above the instrument to minimize
instrument heating while rack mounted. Do not continue to operate the
instrument if you cannot verify the fan is operating (note some fans may have
intermittent duty cycles). Do not insert any object into the fan's inlet or
outlet.
For continued safe use of the instrument
Do not place heavy objects on the instrument.
Do not obstruct cooling air flow to the instrument.
Do not place a hot soldering iron on the instrument.
Do not pull the instrument with the power cord, connected probe, or
connected test lead.
Do not move the instrument when a probe is connected to a circuit
being tested.
vii
Compliance Statements
This product is subject to Directive 2002/96/EC of
the European Parliament and the Council of the
European Union on waste electrical and electronic
equipment (WEEE), and in jurisdictions adopting
that Directive, is marked as being put on the
market after August 13, 2005, and should not be
disposed of as unsorted municipal waste. Please
utilize your local WEEE collection facilities in the
disposition of this product and otherwise observe
all applicable requirements.
Disposal of Old Electrical & Electronic Equipment (Applicable in the
European
Union and other European countries with separate collection systems)
viii
CE Declaration of Conformity
This instrument meets the requirements of 2006/95/EC Low Voltage Directive
and 2004/108/EC Electromagnetic Compatibility Directive with the following
standards.
Low Voltage Directive
- EN61010-1: 2001
EMC Directive
- EN 61000-3-2: 2006
- EN 61000-3-3: 1995+A1: 2001+A2: 2005
- EN 61000-4-2 / -3 / -4 / -5 / -6 / -11
- EN 61326-1: 2006
ix
Safety Symbols
Refer to the user manual for warning information to
avoid hazard or personal injury and prevent damage to
instrument.
Electric Shock hazard
Alternating current (AC)
Chassis (earth ground) symbol.
Ground terminal
On (Power). This is the In position of the power switch
when instrument is ON.
Off (Power). This is the Out position of the power
switch when instrument is OFF.
CAUTION indicates a hazardous situation which, if not
avoided, will result in minor or moderate injury
WARNING indicates a hazardous situation which, if not
avoided, could result in death or serious injury
DANGER indicates a hazardous situation which, if not
avoided, will result in death or serious injury.
NOTICE is used to address practices not related to
physical injury.
x
Table of Contents
Safety Summary ......................................................................... i
Compliance Statements ..................................................................... viii
Safety Symbols ...................................................................................... x
1 General Information ...................................................... 1
1.1 Product Overview ....................................................................... 1
1.2 Package Contents ....................................................................... 1
1.3 Front Panel Overview ................................................................. 3
Front Panel Description .............................................................. 3
1.4 Keypad Overview ........................................................................ 4
Main Keypad Description............................................................ 4
Menu Keypad Description ........................................................... 5
1.5 Rear Panel Overview .................................................................. 6
Rear Panel Description ................. Error! Bookmark not defined.
1.6 Display Overview ........................................................................ 7
Display Description ..................................................................... 7
2 Getting Started ............................................................. 8
2.1 Input Power Requirements ........................................................ 8
Input Power ................................................................................ 8
Fuse Requirements ..................................................................... 9
Fuse Replacement ....................................................................... 9
2.2 Preliminary Check ..................................................................... 10
3 Making Measurements ............................................... 11
3.1 Open and Short Calibration ...................................................... 11
Open Calibration....................................................................... 11
xi
Short Calibration....................................................................... 11
3.2 Parameter Entry ....................................................................... 12
3.3 Impedance Parameters ............................................................ 14
Series and Parallel Models........................................................ 16
Choosing a Test Frequency ....................................................... 17
Choosing a Measurement Circuit Model .................................. 18
3.4 Configure Basic Measurement ................................................. 21
Primary Parameters .................................................................. 21
Secondary Parameters .............................................................. 22
Parameter Combinations .......................................................... 23
Measurement Options .............................................................. 23
Measurement Display............................................................... 24
3.5 Bin Sorting Function ................................................................. 26
Absolute Mode ......................................................................... 27
Tolerance Mode ........................................................................ 28
Bin Display ................................................................................ 30
Table Display ............................................................................. 30
Histogram Display .................................................................... 31
Configure Bin Function ............................................................. 32
3.6 Sweep Function ........................................................................ 35
Linear Sweep Mode .................................................................. 35
Logarithmic Sweep Mode ......................................................... 36
Table Display ............................................................................. 36
Configure Sweep Function ........................................................ 37
AUTOSCALE ............................................................................... 39
AUTOFREQ ................................................................................ 39
INTERP ...................................................................................... 39
xii
4 System ........................................................................ 43
System Information .................................................................. 44
System Setup ............................................................................ 46
Communication Setup .............................................................. 48
5 Save/Recall ................................................................. 49
Save/Recall a Measurement Configuration .............................. 51
Save a Measurement Result ..................................................... 54
Save a Screenshot ..................................................................... 57
6 Remote Interface ........................................................ 59
6.1 Interface Configuration ............................................................ 59
USB (Virtual COM) .................................................................... 59
GPIB .......................................................................................... 60
LAN (Ethernet) .......................................................................... 60
6.2 Parameter Definition ................................................................ 65
6.3 Error/Event List ......................................................................... 66
6.4 SCPI Common Commands ........................................................ 67
6.5 SCPI Command Subsystem ....................................................... 67
7 Troubleshooting Guide ................................................ 75
8 Specifications .............................................................. 76
Basic Measurement Function ................................................... 76
Measurement Accuracy ............................................................ 78
SERVICE INFORMATION ........................................................... 84
LIMITED THREE-YEAR WARRANTY ............................................ 85
xiii
1 General Information
1.1 Product Overview
The B&K Precision model 891 bench LCR meter is a high accuracy component
tester that is capable of testing inductors, capacitors and resistors with
adjustable test frequency from 20 Hz to 300 kHz. The 891 has a 2U half rack
form factor and is suitable for standard rack mount installation. With the
vivid 4.3-inch color graphic LCD, users can operate and read the
measurements easily.
Integrated BIN comparator function enables model 891 Bench LCR Meter to
quickly sort components up to 10 bins. The easy to operate sweep function
provides a quick look of the component characteristics over any range of test
frequencies. With built-in USB, GPIB and Ethernet interfaces, the 891 can be
remotely controlled to perform daily operations in production, quality control
and laboratory environments.
Features:
Best accuracy 0.05%
Test frequency from 20 Hz to 300 kHz
Frequency sweep function
Bin sorting comparator
Adjustable measurement speed for fast readout or better accuracy
Standard USB, GPIB and Ethernet interface
Save and recall up to 10 internal measurement setups
4.3” color TFT LCD with 480 x 272 pixels
1.2 Package Contents
Please inspect the instrument mechanically and electrically upon receiving it.
Unpack all items from the shipping carton, and check for any obvious signs of
physical damage that may have occurred during transportation. Report any
damage to the shipping agent immediately. Save the original packing carton
for possible future reshipment. Every instrument is shipped with the
1
following contents:
1 x Model 891 bench LCR meter
1 x User Manual
1 x AC power cord
1 x 4-wire Kelvin clip test lead
1 x Certificate of calibration
1 x Test report
Verify that all items above are included in the shipping container. If anything
is missing, please contact B&K Precision.
2
Power On/Off Switch
Menu Keys
Measurement Terminal
Save/Recall Keys
Numeric Keypad
Arrow Keys
Local Key
Softkeys
4.3” TFT Color LCD Display Window
USB Host Port
1
2
3
4
5 6 7
8
9
10
1
2 4 3
9 5 6 7 8
10
1.3 Front Panel Overview
Figure 1.1 – Front Panel Overview
Front Panel Description
3
Local: Switch to local operation
Recall: Recall the configuration from internal memory or
external USB flash.
Save: Save the configuration, screen and result to
internal memory or external USB flash.
Up: Moves the cursor up
Down: Moves the cursor down
Left: Moves the cursor left
Right: Moves the cursor right
Decimal: Decimal point during numeric entry
Sign: Plus or minus sign during a numeric entry
1.4 Keypad Overview
Figure 1.2 – Main Keypad Overview
Main Keypad Description
4
MEAS
FUNC
Measurement function selection of C, L, Z, R and DCR
BIN
Bin comparator measurement of tolerance mode and
absolute mode
SWEEP
Frequency sweep measurement
DISP
Display option configuration
SYSTEM
System settings menu
Figure 1.3 - Menu Keypad Overview
Menu Keypad Description
5
Power On/Off Switch
Menu Keys
Measurement Terminal
Save/Recall Keys
Numeric Keypad
Arrow Keys
Local Key
1 2 3
4
5 7 6
1
2 3 4
5
6
7
1.5 Rear Panel Overview
Figure 1.4 - Rear Panel Overview
Rear Panel Description
6
Main Display Area
Displays measurement conditions and measurement results
corresponding to the measurement modes.
Menu Functions
Displays the current measurement mode.
Menu Options
Displays label options corresponding to the active field.
1 2 3
2
1
3
1.6 Display Overview
Figure 1.5 – Display Overview
Display Description
7
The included AC power cord is safety certified for this
instrument operating in rated range. To change a cable or
add an extension cable, be sure that it can meet the
required power ratings for this instrument. Any misuse
with wrong or unsafe cables will void the warranty.
2 Getting Started
Before connecting and powering up the instrument, please review and go
through the instructions in this chapter.
2.1 Input Power Requirements
Input Power
The instrument has a selectable AC input that accepts line voltage and
frequency input within:
AC Input: 104 – 126 V / 207 – 253 V (selectable)
Frequency: 47 – 63 Hz
Before connecting to an AC outlet or external power source, be sure that the
voltage selection switch is at the correct position of 115 V or 230 V and the
power switch is in the OFF position. Also, verify that the AC power cord,
including the extension line, is compatible with the rated voltage/current and
that there is sufficient circuit capacity for the power supply. Once verified,
connect the cable firmly.
8
Before replacing fuse, disconnect AC input power cord first
to prevent electric shock.
Only use same rating of the fuse. Using a different rated
fuse may damage the instrument.
Model
Fuse Specification (115 V)
Fuse Specification (230 V)
891
T 1 A, 250 V
T 500 mA, 250 V
Fuse Requirements
An AC input fuse is necessary when powering the instrument. The fuse is
located at the back of the instrument. In the event the fuse needs to be
replaced, make sure the AC input power cord is disconnected from the
instrument before replacing. Refer to the table below for the fuse
requirements with either 115 VAC or 230 VAC.
Table 2.1 – Fuse Requirements
Fuse Replacement
Follow the steps below to replace or check the fuse.
1. Locate the fuse box in the rear panel of the instrument, next to the
AC input receptacle.
2. Use a flat blade screwdriver and turn the fuse capsule counter-
clockwise. There is an internal spring that will push it out after
turning.
3. Pull out the glass tube fuse inside to check and replace as necessary.
4. Insert the fuse capsule in the same location and use the flat blade
screwdriver to turn clockwise.
9
5. The fuse capsule will now be locked and secured.
2.2 Preliminary Check
Complete the following steps to verify that the generator is ready for use.
1. Verify AC Input Voltage
Verify and check to make sure proper AC voltages are available to
power the instrument. The AC voltage range must meet the
acceptable specification as explained in section 2.1.
2. Connect Power
Connect AC power cord to the AC receptacle in the rear panel and
press the power switch to the ON position to turn ON the instrument.
The instrument will have a boot screen while loading, after which the
main screen will be displayed.
3. Self Adjust
At power-on, the waveform generator performs a diagnostic self-test
procedure to check itself for errors.
10
3 Making Measurements
3.1 Open and Short Calibration
The 891 provides open/short calibration capability to have better accuracy in
measuring high and low impedance. It is recommended that the user perform
open/short calibration if the test leads or the test fixture has been changed.
Open Calibration
The open calibration feature compensates for any stray admittances that may
exist within the test fixture or leads. Disconnect any device under test from
the test leads or test fixture and make sure the test terminals are open
(nothing connected). Press SYSTEM → CAL → OPEN CAL keys to start the
open calibration.
Figure 3.1 – Open Calibration
This open calibration takes about 1 minute to complete. After it is finished,
the 891 will beep rapidly to inform that the calibration is done.
Short Calibration
The short calibration feature compensates for any residual impedances that
11
may exist within the test fixture or leads. To perform the short calibration,
connect all four terminals on the test leads or insert the Shorting Bar into the
test fixture. Press SYSTEM → CAL → SHORT CAL keys to start the short
calibration.
Figure 3.2 – Short Calibration
This short calibration takes about 30 seconds. After it is finished, the 891 will
beep rapidly to inform that the calibration is done.
3.2 Parameter Entry
The test parameters on different measurement functions can vary. But, they
all have similar methods to enter the parameters. The following list explains
the general method of test parameter entry.
1. Use any arrow key to activate the selection cursor.
12
Figure 3.3 – Parameter Selection
2. Use , , or arrow keys to move the cursor to the
corresponding parameter field for editing.
3. If the parameter is a numeric value, use the numeric keypad to enter
the desired value followed by unit selection using the option softkeys.
Figure 3.4 – Digit Selection Entry
4. Or, use the and arrow keys on the option softkey to move
the cursor left and right to selected desired digit of increase or
13
decrease. Use the INC or DEC on the softkey to increase or decrease
the parameter value.
5. If the parameter is a selection value, press the desired selection on
the option softkey.
Figure 3.5 – Selection Entry
3.3 Impedance Parameters
Components such as inductors (L), capacitors (C), and resistors (R) can
respond to test signals with varying frequencies and levels in different ways.
Large capacitors tested at high frequencies can respond differently than when
tested at lower frequencies. Large inductors tested at low frequencies can
respond differently than when tested at higher frequencies. In contrast,
resistors will respond relatively the same at high or low frequencies. Due to
these characteristics, it is very important to understand the complex
impedance parameters of the electronic components. The 891 LCR meter
allows users to vary these test signals’ measurement frequency,
measurement level, and equivalent circuit choice to characterize the
component under test.
When we analyze the impedance using the impedance measurement plane
(Figure 3.6), it can be visualized by the real element (Resistance) on the X-axis
and the imaginary element (Reactance) on the Y-axis. This impedance
14
measurement plane can also be seen as polar coordinates. |Z| is the
magnitude and θ is the phase of the impedance.
Figure 3.6 – Complex Impedance Plane
X
There are two different types of reactance: Inductive (XL) and Capacitive (XC).
It can be defined as follows:
15
For components, the quality factor (Q) serves as a measurement of the
reactance purity. In the real world, there is always some associated resistance
that dissipates power, decreasing the amount of energy that can be
recovered. The quality factor can be defined as the ratio of the stored energy
(reactance) and the dissipated energy (resistance). Q is generally associated
with inductors and D (dissipation factor) for capacitors. Below shows the
relationships between these parameters:
Series and Parallel Models
Components are modeled with one of the two following equivalent circuits:
16