Tonghui TH2821B User manual

OPERATION MANUAL
English
February 2006
TH2821B
Portable LCR Meter

TH2821B OPERATION MANUAL
2
Contents
Contents ........................................................... 2
How to Contact Us....................................... 3
Incoming Inspection..................................... 4
Notes on Use............................................... 5
Warranty: ................................................... 6
Chapter 1 Overview........................................... 7
1.1 Introduction .......................................... 7
1.2 Main Functions ...................................... 7
1.3 Specifications........................................ 8
1.4 Environment Requirements .................. 10
Chapter 2 Panel Illustration............................. 11
2.1 LCD Display Illustration ........................ 11
2.2 Keyboard Illustration ........................... 13
Chapter 3 Operation........................................ 14
3.1 Power on............................................. 14
3.2 How to operate ................................... 15
3.2.1 Key Functions ............................ 15
3.3 Battery Replacement ........................... 21
3.4 Clearing Instruction ............................. 22
Appendix......................................................... 23

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Incoming Inspection
Inspect the shipping container for damage. The contents of
the shipment should be listed as follows. If the contents are
incomplete, if there is damage or defect, please contact
our company or your nearest Sales and Service Office.
Accessories
TH26028 DC Power Adapter 1
TH26027 4 terminal Kelvin test clip leads 1
1604A 9V battery 1
User Manual 1
Options
TH26029 SMD component test fixture

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Notes on Use
zThis meter is only for indoor use.
zTurn off the TH2821B while switching the power supply
between battery and DC adapter or replacing the
battery.
zAlthough internal circuit protection is provided, DC
voltage or current may damage TH2821B. Before you
measure a capacitor, be sure the capacitor is fully
discharged.
zTake out the battery when the meter is not in use for
more than 3 months.
zA single standard 9V battery can be used for the power
supply. TH2821B will not work normally when battery
voltage is less than 6V.
zThe 12V AC to DC adaptor is recommended to be used
for TH2821B power supply.
zPerform Open and Short corrections for accurate
measurement especially when test fixture is changed.
zThe functions locked with password are not accessible
by users.

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Warranty:
This instrument product is warranted against defects in
material and workmanship for a period of two years from
the date of shipment. During the warranty period, Our
company will, at its option, either repair or replace
products which prove to be defective. For warranty service
or repair, this product must be returned to a service facility
designated by our company.
Warranty limitation
The foregoing warranty shall not apply to defects resulting
from improper or inadequate maintenance by Buyer,
Buyer-supplied software or interfacing, unauthorized
modification or misuse, or improper site preparation or
maintenance.

Chapter 1 Overview
Thank you for purchasing our product. To get the maximum
performance from the instrument, please read this manual
first, and keep this manual at hand.
1.1 Introduction
TH2821B is a microprocessor-controlled portable meter with
low power consumption. It can measure six basic parameters,
they are inductance L, capacitance C, resistance R,
impedance |Z|, dissipation factor D and quality factor Q.
TH2821B can fulfill the measurement needs of various
component manufacturers and maintenance technicians.
1.2 Main Functions
1．Test Parameter
L-Q, C-D, R-Q and Z-Q.
2．Correction
OPEN: multi-frequency correction of open circuit;
SHORT: multi-frequency correction of short circuit.
3．Display Mode
Direct —— direct measurement value;
4．Range Hold
When measuring a large number of components with
the same nominal value, this function can effectively
improve the measuring rate.
5．Equivalent Circuit Mode
Both parallel and series equivalent circuit modes can

TH2821B OPERATION MANUAL
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be obtained.
6．Data Hold
This function can be used to freeze the current display
value.
1.3 Specifications
Parameter L-Q, C-D, R-Q and Z-Q
Frequency 100 Hz, 120 Hz and 1 kHz
Accuracy Basic Accuracy: 0.3%
Display 5digits display for both primary and secondary
parameters
100 Hz,120 Hz 1 μH – 9999 H
L
1 kHz 0.1 μH – 999.9 H
100 Hz, 120Hz 1 pF – 9999 μF
C
1kHz 0.1 pF – 999.9 μF
R, |Z|
0.0001 Ω- 999.9 MΩ
D, Q 0.0001 – 9999
Measurem
ent Range
Δ% 0.0001% - 9999%
1kHz 0.3 Vrms (1±10%)
Test Level
(Range
Auto and
Open
Circuit) 100Hz
120Hz
0.3 Vrms (1±15%)
Ranging
Mode Auto and Hold
Equivalent
Circuit Parallel and Series
Display Direct

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(Continued)
Correction Open and Short Zeroing
Rate Approx. 3 meas/sec
Terminals 5 terminals
Power Supply 1604 9V battery or DC12V(100 mA) adapter
Low Battery
Indication Approx. 6V
Power
Consumption Normal: Approx. 30 mA Auto power-off: Approx. 500 nA
Auto Power
Off time Approx. 30 minutes
Weight Approx. 400 g
Dimensions 200mm(L) × 95mm(W) × 40mm(D)
Table 1-1 Specifications
*Note：
Primary parameter accuracy(Ae)
C：Ae = 0.3%(1+Cx/Cmax+Cmin/Cx)
L：Ae = 0.3% (1+ Lx/Lmax+ Lmin/Lx)
Z：Ae = 0.3% (1+ Zx/Zmax+ Zmin/Zx)
R：Ae =0.3%(1+ Rx/Rmax+ Rmin/Rx)

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Max and Min values are as follows：
Parameter Range Auto
Cmax 80μF/f
Cmin 150pF/f
Lmax 159H/f
Lmin 0.32mH/f
Zmax 1MΩ
Zmin 1.59Ω
Here：Zmax = Rmax; Zmin = Rmin, Frequency unit: kHz.
Secondary parameter accuracy
De= Ae/3 when Dx ≤0.1
De= Ae(1+Dx)/3 when Dx＞0.1
Qe=ex
ex DQ DQ
×
×
±μ1 when Qx·De<1
1.4 Environment Requirements
1．Please do not operate TH2821B under the following
environment conditions, as any of them will directly
affect measuring precision or damage the meter:
zPlease do not operate the instrument in places
where is dusty, vibrant, under direct sunlight, or
where there is corrosive air.
zAlthough TH2821B has been specially designed
for reducing the noise caused by AC power, the
environment with low noise is still recommended.
If this can not be arranged, please make sure to
use power filter for the AC-DC adaptor.
2．The TH2821B must be operated under the following
environment conditions:
Temperature: 0°C ~ 40°C,
Humidity: ≤90% RH at 40°C.
3．Storage Temperature: -25°C ~ 50°C.

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Chapter 2 Panel Illustration
2.1 LCD Display Illustration
Figure 2-1 LCD Display

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No. Description No.
Description
1 Battery Power
Indicator 8 Unit Indicator
2 Remote
Indicator 9 Ranging Mode Indicator
3 Beeper
Indicator 10
Primary Parameter
Display
4 Series/Parallel
Indicator 11
Frequency Indicator
5 Comparator
Indicator 12
Primary Parameter
Indicator
6
Secondary
Parameter
Indicator
13
2nd Function Indicator
7
Secondary
Parameter
Display
14
DC Adaptor Power Supply
Indicator
Table 2-1 LCD Description
Others:
DH: Data hold indictor
CAL: Correction function indictor
MENU: Menu operation indictor

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2.2 Keyboard Illustration
Figure 2-2 Keyboard
No. Key Function
○
1 POWER
Power On/Off
○
2 PARA Parameter Selection
○
3 FREQ Frequency Selection
○
4 CLEAR
CLEAR Selection
○
5 RANGE
Range Selection
○
6 AUTO Range Auto Selection
○
7 DH Data Hold
○
8 EQU Series/Parallel
Indicator
Table 2-2 Key Description

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Chapter 3 Operation
3.1 Power on
1. Press POWER key to turn on TH2821B.
2. The operation system version will be displayed.
3. At last the instrument enters the measurement state.
Figure 4-1 Measurement Display
Measurement display description:
1. Battery Supply 3. Beeper ON
4. Series Circuit 5. Sorting Result: P1
6. Parameter D 7. Secondary parameter
8. Unit 9. Range 0 (Auto)
10. Primary parameter 11. Frequency: 1 kHz
12. Parameter C

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3.2 How to operate
3.2.1 Key Functions
1. Parameter Setup：
Press PARA key to select the following measurement
parameter combinations：L-Q, C-D, R-Q and Z-Q.
Units Description:
L μH mH H
C pF nF μF
R/|Z| ΩkΩMΩ
Table 4-1 Units
|Z| is the absolute value of impedance. Measurement
value of L, C or R may be positive or negative. Negative
capacitance value means that the device under test is
actually an inductor; also negative inductance value means
that the device under test is actually a capacitor. In theory
R should be positive constantly, under some condition, R
may be negative due to over zero correction. Please carry
out correct zero correction.
The maximum number of display digits is 5, but 5-digit is
not always available and 4-digit is displayed sometimes.
The conversion is described in the following description:
From 4-digit to 5-digit:
When the first 2 digit of current value is less than 18.
From 5-digit to 4-digit:
When the first 2 digit of current value is more than 20.
2. Frequency Setup:
Use FREQ key to select the following test frequencies in
turn: 100 Hz, 120 Hz and 1 kHz.

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3. Range Setup:
RANGE and AUTO keys are used to set the measurement
range. AUTO key toggles ranging mode between “Auto”
and “Hold”. RANGE keys are used to increase or decrease
the measurement range, if the current ranging mode is
“Auto”, then the ranging mode is changed to “Hold” at the
same time.
*Note：
When ranging mode is set to HOLD, the measurement
range is fixed at current range. Overload symbol “-----” will
be displayed if the impedance under test exceeds the
current effective measurement range or display range.
Range
No.
Range
Resistor
Range
Up
Range
Down
0 100kΩ
1 10kΩ
2 1kΩ
3 100Ω
4 20Ω
Ï
20kΩ
Ï
2kΩ
Ï
200Ω
Ï
20Ω
Ï
Ð
18kΩ
Ð
1.8kΩ
Ð
180Ω
Ð
18Ω
Ð
Table 4-2 Ranges

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*Note：
How to calculate the measurement range
Example: Assume capacitance C=210pF, dissipation D=0.0010 and
test frequency f=1 kHz.
Solution:
Ω≈
××××
=≈
+=
−9.757
1021010001416.32
1
2
1
2
1
9
X
X
X
XX
fC
Z
fCj
RZ
π
π
From the Table 4-2, we can get the correct measurement range is
No. 2.
4. Data Hold
Press DH key to freeze the display, press DH key again to
release.
5. Correction Function
zPress CLEAR key to select the second function,
“SHIFT” will be lighted on the screen.
zPress CLEAR key to enter the correction function, the
following information will be displayed on the screen.
Figure 4-2 Correction Display
zClear (Clear) is displayed in the primary parameter
display area, OpeN (OPEN), Short (Short) or Quit

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(Quit) will be displayed in the secondary parameter
display area.
*Note：
OpeN (OPEN), Short (Short) and Quit (Quit) are selected and
displayed automatically by the meter according to the impedance
value of the device under test.
zPress any key to cancel the correction operation and
return to the measurement state. Press CLEAR key to
start the correction measurement.
zWhen correction measurement is finished, PASS or FAIL
will be displayed on the screen, see Figure 4-3
Figure 4-3 Open correction Passed
*Note：
1．The correction function must be used for accurate measurement.
The correction function can eliminate the stray admittance
(capacitance, and inductance) and the residual impedance
(resistance and reactance) induced by test fixture, test leads and
instrument itself. Perform the correction operation again if the
measurement conditions are changed such as test fixture and
environment temperature.
2．It is recommended to perform the open and short correction at
the same time.
3．During short correction period, FAIL (FAIL) will be displayed in
the secondary parameter display area when short correction is
failed. Make sure that the measurement contacts are shorted

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reliably and perform the short correction again.
4．Th2821B measures the correction data at all frequency points and
all measurement ranges. The correction data is stored in the
non-volatile memory. So you don’t have to perform the correction
again, if the test conditions are not changed.
5．Open and short corrections are automatically selected by the
instrument according to the impedance value under test. If there
is a component in the fixture or if there is error with the
instrument, Quit (Quit) will be displayed in the secondary
parameter display area.
6. Equivalent Circuit
Press EQU key to select the Series or Parallel circuit
mode.
*Note：
1．The actual C, R and L are not the ideal pure C, R and L. Normally
an actual component can be regarded as the combination of an
ideal resistor and an ideal reactor in series or parallel circuit
mode.
2．TH2821B can convert between the two different equivalent
circuit modes using the following equations. The measurement
values of the two different circuit modes maybe different under
different quality factor Q (or dissipation factor D).
Capacitance Cp: from parallel to series
Circuit Mode：
Cp
Rp
Dissipation：
QRfC
D
PP
1
2
1==
π
Series：
)1(
)1(
22
2
DDRR
CDC
PS
PS
+=
+=

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Capacitance Cs：from series to parallel
Circuit Mode：Cs Rs
Dissipation: Q
CfRD SS
1
2==
π
Parallel:
22
2
)1(
)1(1
DDRR
CDC
SP
SP
+=
+=
Inductance Lp：from parallel to series
Circuit Mode：
Lp
Rp
Dissipation:
QR
fL
D
P
P1
2==
π
Series:
)1(
)1(1
22
2
DDRR
LDL
PS
PS
+=
+=
Inductance Ls：from series to parallel
Circuit Mode：Lp Rp
Dissipation：
QfL
R
D
S
S1
2==
π
Parallel:
22
2
)1(
)1(
DDRR
LDL
SP
SP
+=
+=
Here parameter with subscript s means the series mode,
parameter with subscript p means the parallel mode.

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3. From the above equations, we can conclude that the conversion
between series and parallel is determined by D2 or Q2（Q=1/D）.
The value of D2 or Q2 directly determined the parameter values in
different circuit mode.
Example:
Three capacitors have the same series capacitance: Cs=0.1μF, b u t
their dissipations are different with each other: D1=0.0100,
D2=0.1000, D3=1.0000. According to the above equation, we can
get their capacitance in parallel mode:
Cp1 = 0.09999 μF
Cp2 = 0.09901 μF
Cp3 = 0.05000 μF
We can find that Cs is almost the same with
Cp when D is very small (Ｄ< 0.01), but when
D is more than 0.01，Cp and Cs are different
obviously. For example: When D = 0.1，the
difference is 1% ， but when D = 1 ， the
difference is almost 50%.
3.3 Battery Replacement
*Note：
The instrument will not be started, when the battery is weakening.
Replace the battery immediately.
zLoosen the three screws with suitable driver and
remove the bottom cover.
zReplace the degraded battery with a new DC 9V
battery.
zModel 1604, 006P or other equivalent battery must be