Tonghui TH2821A User manual

OPERATION MANUAL
TH2821A
Portable LCR Meter

TH2821A 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 ........................................9
1.4 Environment Requirements ...................12
Chapter 2 Panel Illustration..............................13
2.1 LCD Display Illustration.........................13
2.2 Keyboard Illustration ............................15
Chapter 3 Operation.........................................17
3.1 Power on .............................................17
3.2 How to operate....................................18
3.2.1 First Key Functions .....................18
3.2.2 Second Key Functions: ................20
3.3 Battery recharge ..................................30
3.4 Clearing Instruction..............................31
Appendix .........................................................32

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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
LH-200H7C rechargeable battery(inside) 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 TH2821A 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 TH2821A. Before you
measure a capacitor, be sure the capacitor is fully
discharged.
zCharging may disturb measurement result sometimes.
zNickel Metal Hydride rechargeable battery can be used
for the power supply. TH2821A will not work normally
when battery voltage is less than 6V.
zThe 12V AC to DC adaptor is recommended to be used
for TH2821A 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.

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
TH2821A 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.
TH2821A 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;
Δ—— absolute deviation;
Δ% —— percent deviation.
4．Range Hold
When measuring a large number of components with
the same nominal value, this function can effectively
improve the measuring rate.

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5．Comparator Function
Built-in 4 Bins comparator: NG, P1, P2 and P3.
6．Equivalent Circuit Mode
Both parallel and series equivalent circuit modes can
be obtained.
7．Data Hold
This function can be used to freeze the current display
value.
8．Alarm Mode
NG, P1, P2, P3 and OFF modes can be selected.

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1.3 Specifications
Parameter L-Q, C-D, R-Q and Z-Q
Frequency 100 Hz, 120 Hz , 1 kHz and 10 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,10 kHz 0.1 μH – 999.9 H
100 Hz, 120Hz 1 pF – 9999 μF
C
1kHz,10 kHz 0.1 pF – 999.9 μF
R, |Z| 0.0001 Ω- 999.9 MΩ
D, Q 0.0001 – 9999
Measurement
Range
Δ% 0.0001% - 9999%
10kHz 0.1 Vrms (1±15%)
120Hz
1kHz 0.3 Vrms (1±15%)
Test Level
(Range Auto
and Open
Circuit) 100Hz 0.42 Vrms (1±15%)
Ranging Mode Auto and Hold
Equivalent
Circuit Parallel and Series
Display Direct, ΔABS and Δ%
Correction Open and Short Zeroing
Rate Approx. 3 meas/sec
Terminals 5 terminals

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(Continued)
Comparator 4 Bins：NG, P1, P2 and P3
Δ% -9999% - 99999%
L 0.0001 μH – 99999 H
C 0.0001 pF – 99999 μF
R 0.0001 Ω- 99999 MΩ
Limit Setup
Range
Nominal
Z 0.0001 Ω- 99999 MΩ
Alarm Mode NG, P1, P2, P3 and OFF
Power Supply 9V rechargeable battery or DC12V(100 mA)
adapter
Low Battery
Indication Approx. 6V
Power
Consumption Normal: Approx. 25 mA Auto power-off: Approx. 500 nA
Auto Power
Off time Approx. 5 minutes
Weight Approx. 400 g
Dimensions 200mm(L) × 95mm(W) × 40mm(D)
Table 1-1 Specifications

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*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)
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

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1.4 Environment Requirements
1．Please do not operate TH2821A 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 TH2821A 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 TH2821A 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
DHSHIFT
PARA
POWER
ENTER
MENU
ESC
CLEAR LIMIT
DISPLAY
EQU
▲
BUZZER
▲
①②③④
⑤⑥⑦⑧
FREQ
AUTO
U
V
Figure 2-2 Keyboard
ÂConvention：
Key Function Conventions
1st function: PARA
2nd function: CLEAR
3rd function: 

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No. Key Function SHIFT+
Key Function
○
1 POWER Power
On/Off
○
2 PARA Parameter
Selection CLEAR Correction
key
○
3 U Range Up LIMIT Sorting Limit
Setup
○
4 FREQ Frequency
Selection MENU Auxiliary
Menu
○
5 AUTO Range Auto
Selection DISPLAY Display Mode
Selection
○
6 VRange Down BUZZER Alarm Mode
Setup
○
7 DH Data Hold EQU Equivalent
Circuit
○
8 SHIFT 2nd Function
Table 2-2 Key Description
The 3rd Functions：
, , , , and are valid during Menu
setup and Data input operations.

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Chapter 3 Operation
3.1 Power on
1. Press POWER key to turn on TH2821A.
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 First 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 ，1 kHz and 10 kHz.

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3. Range Setup:
U, Vand AUTO keys are used to set the measurement
range. AUTO key toggles ranging mode between “Auto”
and “Hold”. Uand Vkeys 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.
3.2.2 Second Key Functions:
1. Correction Function
zPress 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

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zClear (Clear) is displayed in the primary parameter
display area, OpeN (OPEN), Short (Short) or Quit
(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 key to cancel the correction operation and
return to the measurement state. Press 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
zPress key to abort the current correction data
measurement and return to the measurement. The
previous correction data will still be stored.
*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

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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
reliably and perform the short correction again.
4．TH2821A 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.
2. Equivalent Circuit
zPress key to select the second function, “SHIFT”
will be lighted on the screen.
zPress EQU key to select the Series or Parallel circuit
mode. (Refer to Figure4-1)
*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．TH2821A 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