Tonghui TH2617 User manual

OPERATION MANUAL
TH2617
PRECISON LCR METER

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Contents
1Chapter I Generals .................................................................... 2
1.1 Introduction ......................................................................... 2
1.2 Technical Specifications ............................................................... 3
1.2.1 Measurement Parameters ............................................................. 3
1.2.2 Measurement Terminals .............................................................. 3
1.2.3 Test Frequency ..................................................................... 3
1.2.4 Display Range ...................................................................... 3
1.2.5 Measurement Accuracy............................................................... 3
1.2.6 Measurement Level .................................................................. 4
1.2.7 Measurement Speed ................................................................. 5
1.3 Functions ........................................................................... 5
1.3.1 Average of Measurement Values ....................................................... 5
1.3.2 Correction ......................................................................... 5
1.3.3 Equivalent Circuit ................................................................... 5
1.3.4 Measurement Mode.................................................................. 6
1.3.5 Range Hold ........................................................................ 6
1.3.6 Display Mode ...................................................................... 6
1.3.7 Sorting Function .................................................................... 6
1.3.8 Print Function ...................................................................... 6
1.3.9 RS-232C Serial Interface ............................................................. 6
1.3.10 Handler Interface................................................................... 7
1.3.11 Other Functions.................................................................... 7
1.4 Front and Rear Panel .................................................................. 7
1.4.1 A Tour of the Front Panel............................................................ 7
1.4.2 Description of the Rear Panel .......................................................... 9
1.5 Operating Environment ................................................................9
1.5.1 Temperature and Humidity ............................................................ 9
1.5.2 Power Supply ...................................................................... 9
1.5.3 Dimensions ........................................................................ 9
1.5.4 Weight ............................................................................ 9
2Chapter ⅡOperation Instruction...................................................... 11
2.1 Keyboard and Function of the Meter ..................................................... 11
2.2 Conversion of Menus ................................................................. 12
2.3 Functions Setup in the First Menu ....................................................... 13
2.3.1 Measurement Parameter ............................................................. 14
2.3.2 Display Mode ..................................................................... 14
2.3.3 Measurement Level ................................................................. 16
2.3.4 Measurement Speed ................................................................16
2.3.5 Measurement Range ................................................................17
2.3.6 CONT and SINGLE Mode ........................................................... 18
2.4 Functions in the Second Menu.......................................................... 19
2.4.1 Set the Test Frequency .............................................................. 20

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2.4.2 Equivalent Model .................................................................. 20
2.4.3 D Displayed in PPM Mode ........................................................... 22
2.4.4 Volume and State of Alarm........................................................... 22
2.4.5 Correction ........................................................................ 22
2.5 Sorting Function..................................................................... 24
2.5.1 Introduction of Sorting .............................................................. 24
2.5.2 Limits and Nominal Setup............................................................ 24
2.5.3 Example of Sorting ................................................................. 28
2.6 Handler Interface .................................................................... 28
2.6.1 Operation......................................................................... 29
2.6.2 Connector of HANDLER Interface..................................................... 30
2.7 Standard Printer Interface.............................................................. 30
2.7.1 Introduction of Printer Interface ....................................................... 30
2.7.2 Print Format ...................................................................... 31
2.8 Serial Interface(RS-232C) ............................................................. 32
3ChapterⅢMeasurement Basics and Troubleshooting...................................... 38
3.1 Unpacking and Measurement........................................................... 38
3.1.1 Attention ......................................................................... 38
3.1.2 Measurement Basics ................................................................38
3.2 Connection of Component ............................................................. 40
3.2.1 Measurement of Capacitor ........................................................... 40
3.2.2 Connect the Component ............................................................. 40
3.2.3 Eliminate the Influence of Stray Impedance .............................................. 40
3.2.4 DC Bias .......................................................................... 42
3.3 Troubleshooting ..................................................................... 42
4Chapter ⅣPacking and Warranty ..................................................... 45
4.1 Packing............................................................................ 45
4.2 Warranty........................................................................... 45

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DANGER
The highest external DC bias voltage is 100V. When external dc bias voltage is applied, the
high voltage exists between the test terminals of the meter. Special care should be taken when
carrying out test to avoided injury of human body caused by electrical shock. When making test
with external bias voltage applied, please do not contact directly or plug in/draw out the
component under test on the test fixture or test cable because leads of the tested component are
of high voltage.
WARNING
To avoid electric shock hazard, please make sure that phase line, zero line and ground line are
connected correctly before the meter is plugged into an outlet. The instrument chassis and
cabinet must be connected to a safety earth ground to avoid the cover to be electrified.
WARNING
Only qualified maintenance person can remove instrument cover to make maintenance and
adjustment. The plug of power supply should be drawn out when replacing components. Take
care not to contact the parts with 220V when making maintenance to avoid the hazard of
electrical shock. It is absolutely prohibited to perform normal measurement when the cover is
removed (except for maintenance and adjustment).
ATTENTION
Do not make any component replacement and internal adjustments when the meter is switched
on to avoid unnecessary damage of components or the instrument.
ATTENTION
The calibration of the instrument should be done by professional person, and required operation
on the manual should be completely followed. Should trouble occur, it must be returned to the
company or those qualified service office for service and repair.

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1 Chapter I Generals
1.1 Introduction
TH2617 is a high-precision capacitance meter with wide measurement range. The
instrument provides six typical test frequencies of 100 Hz, 120 Hz, 1 kHz, 10 kHz, 40 kHz and
100 kHz and three test levels of 0.1V, 0.3V and 1.0V for convenient choice, and can measure
various parameters such as capacitance C, equivalent serial resistance ESR, equivalent parallel
resistance EPR, tangent of dissipation angle D, etc. This instrument which merges powerful
functions, excellent performances and simple operation into a whole can satisfy both the need for
fast test in factories, and the requirement of high precision and stable measurement in laboratory.
Meanwhile, the interfaces of Handler and RS-232c make it possible for the instrument to work
with automatic sorting machine and communicate with computer. The measurement conditions
and values can be printed directly through the printer interface. TH2617 really provides
customers an instrument of high performances but low price.
The basic measurement circuits are as follows: sine signal generator with variable
frequencies, test level regulator, precision range resistors, phase detector and A-D converter with
balanced charges. Measurement, calculation, functions and display are controlled by the
microprocessor.
The instrument provides various test conditions such as:
·Test frequency – six typical test frequencies 100 Hz, 120 Hz, 1 kHz, 10 kHz, 40 kHz
and 100 kHz;
·Test signal level – 0.1V, 0.3V and 1.0V;
·Test speed – fast, medium and slow;
·Correction – the meter can perform open and short corrections so as to eliminate the
influence of stray capacitor and cable resistance around test terminals and
improve accuracy.
·Level monitor – level actually applied upon device under test maybe different with that
set in the program due to mismatch between the impedance under test and
the signal source impedance. The function allows you to monitor the actual
voltage level across the device under test and the actual current level
through the device under test.
The instrument provides three kinds of output data and corresponding sorting function:
·Direct – display the value of tested component directly;
Absolute deviation – difference between the measured value and the nominal value;
Percent deviation – difference between the measured value and the nominal value
displayed as a percentage of the nominal value;
·Sorting – three sorting modes of direct, absolute and percent can be selected, and four
bins are available: NG means no good and P1, P2 and P3 mean pass1, pass
2 and pass 3 separately.

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·Print interface – each value of measurement and internal setup parameters can be printed
by a printer with a standard interface;
·Serial interface – RS-232C provides great convenience for communications between the
instrument and computers. All functions and parameters of the meter can be
set through the interface by which functions of the keyboard can almost be
replaced;
·Handler interface – to enable the instrument to operate synchronized with mechanical
equipment, test and sort components and send sorting results to mechanical
equipment.
1.2 Technical Specifications
1.2.1 Measurement Parameters
Capacitances C, resistance R are displayed in Display A with maximum five digits.
Tangent of dissipation angle D is displayed in display B with maximum five digits.
The instrument provides two kinds of equivalent circuits, and in the two circuits, D has the
same values, while C and R have different values. The relations between the two equivalent
circuits are discussed in section 2.3.4.
TH2617 has the following parameters: C/D, R/D, C/C, R/R, and D/D. C/D and R/D can only
be selected in the status of single-frequency. And in the status of double-frequency, the first
parameter is result of Frequency 1. Equivalent mode can be selected in menu.
1.2.2 Measurement Terminals
There are five terminals, namely HD, HS, LS, LD and GND.
1.2.3 Test Frequency
Test frequency: six frequency points of 100 Hz, 120.120 Hz, 1 kHz, 10 kHz, 40 kHz and 100
kHz.
Accuracy of frequency: 0.02%.
Note: 120.120 Hz is regarded as 120 Hz in this manual.
1.2.4 Display Range
C: 0.0001pF ~ 99999μF
R: 0.0001Ω~ 99999MΩ
D: 0.0001 ~ 99999
D ( ppm mode): 1ppm ~ 99999ppm
Δ%: 0.01% ~ 99999%
1.2.5 Measurement Accuracy
C: 0.05% (1+Cx/Cmax+Cmin/Cx) (1+Dx) (1+ks+kv+kf);
R: 0.05% (1+Rx/Rmax+Rmin/Rx) (1+Qx) (1+ks+kv+kf);

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D: ±0.0003 (1+Zx/Zmax+Zmin/Zx) (1+Dx+D2x) (1+ks+kv+kf)+0.0002;
Notes: 1. D is absolute deviations and others are percent deviations;
2. Those with subscript xmean measurement values of the parameters, those with
subscript max mean maximum values and min mean minimum values;
3. ksis the speed factor, kvis the level factor and kfis the frequency factor;
4. In order to gain high measurement accuracy, you should make open and short
correction again when the test fixture or conditions are changed.
5. Zx is impedance of capacitor under test.
1.2.5.1 Speed Factor ks
Fast: ks = 4;
Medium: ks = 1;
Slow: ks = 0.
1.2.5.2 Maximum and Minimum Values For Different Ranges
Table 1-1 Maximum and Minimum Values
Range Hold
Parameter Auto
Range Range 0 Range 1 Range 2 Range 3 Range 4
Cmax 80 μF/f 1000 pF/f 0.1 μF/f 1 μF/f 10 μF/f 80 μF/f
Cmin 150 pF/f 150 pF/f 1900 pF/f 10 nF/f 100 nF/f 1 μF/f
Zmax 1 MΩ1 MΩ159 kΩ15.9 kΩ1.59 kΩ159 Ω
Zmin 1.59Ω15.9 kΩ1.59 kΩ159 Ω15.9Ω1.59 Ω
The unit of f is kHz, when f > 10 kHz, range 0 is not in use; When f > 10 kHz and
measurement range is set to auto, Cmin = 1000 pF/f, Lmax = 25.3 H/f, Zmax = 159 kΩ.
1.2.5.3 Level Factor kv
When V = 1.0V, kv= 0;
When V = 0.3V, kv= 1;
When V = 0.1V, kv= 4.
1.2.5.4 Frequency Factor kf
When f = 100 Hz, 120 Hz or 1 kHz, kf= 0;
When f = 10 kHz, kf= 0.5;
When f = 40 kHz, kf= 2;
When f = 100 kHz, kf= 4.
1.2.6 Measurement Level
Three levels are available: 0.1 V, 0.3 V and 1.0 V (effective value);
Level accuracy: ±(8%×set value) (1+k•f)
Note: The set value of the measurement level is the value set when test terminals are opened
(HD and HS should be connected).

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Here f is measurement frequency with the unit of kHz;
When Range = 0, k = 0.25;
When Range = 1, k = 0.025;
When Range = 2, 3 or 4, k = 0.005.
Due to the output impedance of the signal source, the actual level applied upon the
component under test may be different from the set value. Select V/I display mode, the actual
voltage across the device and current through the device are displayed.
1.2.7 Measurement Speed
Fast: 10times/sec;
Medium: 4times/sec;
Slow: 1.4times/sec.
The actual speed differs with different measurement conditions such as frequency,
component value, display mode (Direct, △or △%), equivalent circuit, trigger mode, range
select mode, average times and so on.
The typical speeds for Fast, Medium and Slow are given under the following measurement
conditions:
· Frequency: 1 kHz;
· Trigger mode: Continuous;
· Range mode: Hold;
· Display parameters: C&D;
· Average times: 1 time.
When some of the functions are in use, test speed will properly be reduced:
a) When print interface is used, the measurement speed varies with the speed of printer;
b) When RS-232C interface is used, it will take 10 to 20 ms additional time. Actual time
is determined by the baud rate of the instrument;
c) The sorting function will spend 5 to 8 ms.
1.3 Functions
1.3.1 Average of Measurement Values
The instrument can calculate the average value of the measurement values and the number
of values averaged can be set form 1 to 99.
1.3.2 Correction
Open correction capability cancels errors due to the stray admittance (G, B) in parallel with
the device under test.
Short correction capability corrects for the residual impedance (R, X) in serial with the
device under test.
1.3.3 Equivalent Circuit
The measurement value of the device under test can be outputted in both series and parallel

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equivalent circuit models.
1.3.4 Measurement Mode
Continuous: the instrument continuously repeats measurements and displays the values after
each measurement;
Single: usually the instrument is in the wait for trigger state, the instrument performs a
single measurement every time a “Start” signal from the keyboard or from the interface is
received. Then it returns to wait for trigger state again and waits for the next “Start” signal.
1.3.5 Range Hold
The instrument is set to the Auto mode when it is switched on. When the measurement range
is set to the Hold mode, the impedance range is fixed at the current range setting.
In the Hold mode, if the measured impedance is out of the effective measurement range,
the instrument will not meet its measurement accuracy specification.
1.3.6 Display Mode
Display window A has four display modes:
—— Direct (actual measurement value of the component under test);
—— △(absolute deviation between the actual measurement value and the nominal value);
—— △% (deviation between the actual measurement value and the nominal value displayed
as a percentage of the nominal value);
—— V/I (effective values of the voltage across the device under test and the current through
the device under test).
1.3.7 Sorting Function
The instrument provides four sorting bins which are described as NG, P1, P2 and P3. NG
means NO GOOD and P1, P2 and P3 means PASS 1, PASS 2 and PASS 3.
There are three sorting modes: direct (DIR), absolute deviation (ABS) and percent
deviation (PER).
The sorting result will be indicated by the sorting indicating lamp in the front panel, and
sorting result can be outputted by the Handler interface when the instrument works in Single
mode and its Handler interface is in “ON” state.
1.3.8 Print Function
The internal parameters, sorting limits and measurement values can be printed out through
the print interface by the printer with a standard interface.
1.3.9 RS-232C Serial Interface
The instrument can be operated by a computer through the serial interface instead of the
keyboard in the front panel, at the same time the instrument can send out the measurement values
to other equipments.

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1.3.10 Handler Interface
When sorting function is selected, Handler interface is set to “ON” state and the instrument
works in Single trigger mode, the instrument will output the bin sorting results, the signal of
busy with A/D conversion and calculation, and the signal of End of A/D conversion. The
instrument can be triggered by the Handler interface.
1.3.11 Other Functions
Except for the described functions, the instrument also provides following functions:
1. Display the measurement values without Open or Short correction;
2. Display the measurement values of D in the ppm mode;
3. Select the alarm function and control the volume of alarm;
4. Select the bin (P1, P2, P3 or NG) to be alarmed.
1.4 Front and Rear Panel
1.4.1 A Tour of the Front Panel
The schematic drawing of the front panel can be seen on the next page.
Description of the front panel:
No. Name Description
1 Display A
Display the measurement values of C and R with five digits.
Three display modes can be selected: Direct, A
b
solute deviation
△and percent deviation △%. It can also display information
when setting parameters.
2 Units of Parameters in
Display A
Indicate the units of main parameter in Direct and Absolute
modes.
3 Display B
Display the measurement values in the status of single-frequency
and double-frequency. It can also display information when
setting parameters.
4 Units of Parameters in
Display B
5 Function Indication For more information, refer to paragraph 2.1.
6 Frame Terminal (GND)
Used for measurement that requires guarding. The Frame
Terminal is tied to the instrument’s chassis, and it is connected
with the protective earth ground of power supply.
7 Test Terminals
8 Trade Mark & Model TONGHUI, TH2617 Capacitance Meter
9 Keyboard Functions and measurement conditions of the instrument can be
selected and controlled by the 6-button keyboard.
10 Sorting Indication When sorting is ON, the LEDS indicate the sorting result.
11 Power ON/OFF
Power ON/OFF Switch. In the “ON” position all operating
voltages are applied to the instrument. In the “OFF” position no
operating voltages are applied to the instrument.
Table 1-2 Description of Front Panel

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1.4.2 Description of the Rear Panel
Description of the rear panel:
No. Name Description of Function
1 RS-232 Serial
Interface (9-Pin)
Provide serial interface between the instrument and peripheral
equipments. Parameters, instructions and measurement results
can be sent and received through the interface.
2 Handler Interface
(9-Pin)
By using the Handler Interface, the instrument can easily be
combined with a component handler, and a system controller to
fully automate component testing, sorting, and quality control
data processing.
3 Print Interface
(25-Pin)
By using the Print Interface, the instrument can be connected to
a printer with a standard print interface. All setup parameters,
measurement values and sorting results can be printed.
4 Fuse Holder Used the correct fuse to protect the instrument, 1A 250Vac.
5 LINE Input
Receptacle
AC power cord receptacle.
6 Nameplate Used to indicate following information: License No., date, serial
number and manufacturer.
Table 1-2 Description of Rear Panel
1.5 Operating Environment
1.5.1 Temperature and Humidity
Temperature: 0℃~ 40℃;
Humidity: ≤90%R.H. at 40℃.
1.5.2 Power Supply
Voltage: 198 ~ 242V;
Frequency: 45 ~ 55Hz;
Power: ≤30W.
1.5.3 Dimensions
350(W) by 110(H) by 340(D) (mm)
1.5.4 Weight
Weight approximately 3.5 kg .

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2 Chapter Ⅱ Operation Instruction
2.1 Keyboard and Function of the Meter
Figure 2-1 Keyboard of TH2617
Figure 2-2 Measurement States of TH2617
TH2617 has only six keys shown as Figure 2-1. These keys are used to select controls and
set parameters. The keys have different functions in different conditions. There are three main
menus. Each menu will be discussed in this chapter.
First Menu: In this menu the instrument performs normal measurements, cursor keys can
be used to select measurement parameters, display mode, test level, speed, range and trigger
mode.
Second Menu: The instrument enters into the second menu by pressing the SET key once
when the instrument is in the first menu. In this menu you can set the test frequency, averaging
rate, equivalent circuit, and so on.

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Third Menu: The instrument enters the third menu by pressing the SET key once again
when the instrument is in the second menu. You should press the SET key twice if the instrument
is in the first menu. All the limits and nominal parameters can be inputted in this menu. If you
press the SET key again in the third menu, the instrument will return to the measuring state (or
the First Menu).
Functions in each menu are listed as follows:
1. The First Menu (or in the measuring state): All functions of this menu are indicated on the
front panel directly, and can be controlled by using the four cursor keys, “∧”, “∨”, “＜” and
“＞” .
A. Measurement Parameters: Cs, Cp, ESR, EPR.
B. Display Mode: Dir (Direct), △(Absolute deviation), △% (Percent deviation) and
V/I (Voltage/Current) can be selected to displayed in the window of Display A;
C. Measurement Level: 1.0V, 0.3V and 0.1V;
D. Measurement speed: FAST, MED (medium) and SLOW;
E. Range Mode: AUTO and HOLD;
F. Trigger Mode: CONT (continuous) and SINGLE.
2. The Second Menu:
A. Measurement Frequency Conversion (FRE--): 100 Hz, 120 Hz, 1 kHz, 10 kHz, 40 kHz,
100 kHz (0.1000, 0.1201, 1.0000, 10.000, 40.000,100.00). In the status of
single-frequency, the frequency is selected to measure;
B. Average Number (AVE--): 1~99 (1, 2, ……, 99);
C. D in PPM Mode (PPD--): On (ON) and Off (OFF);
D. Volume (VOL--): High (Hi), Low (Lo) and Off (OFF);
E. Alarm Bin (ALA--): PASS 1 (P1), PASS 2 (P2), PASS 3 (P3), NO-GOOD (NG);
F. No Correction (NCL--): On (ON) and Off (OFF);
G. Serial Interface (RSC--): On (ON) and Off (OFF);
H. Print Interface (PRN--): On (ON) and Off (OFF);
I. Handler Interface (HAN--): On (ON) and Off (OFF);
J. Sorting Mode (SOR--): Percent deviation △% (PER), Absolute deviation △(ABS),
Direct (DIR) and off (OFF);
K. Correction (CLR--): Open Correction (OPEN) and Short Correction (SHORT).
3. The Third Menu:
A. High Limit of Bin 1 (P1¯--);
B. Low Limit of Bin 1 (P1_--);
C. High Limit of Bin 2 (P2¯--);
D. Low Limit of Bin 2 (P2_--);
E. High Limit of Bin 3 (P3¯--);
F. Low Limit of Bin 3 (P3_--);
G. High Limit of D (D¯--);
H. Nominal Value (STD).
2.2 Conversion of Menus
Previous paragraph described the menus and the functions of each menu. The conversions

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from one menu to another menu are described as follows:
The instrument is in the First Menu when it is switched on. You can set the functions in this
menu. If you want to set the functions in other menus, you should change to the corresponding
menu first. Following figure tells us how to change the menu:
SET SET
START START SET
Figure 2-3 Conversion of Menus
Press ∧, ∨, ＜and ＞in each menu, you can select and control the functions of the
instrument. You should return to the First Menu (Measurement State) to continue your
measurement after functions setup.
Descriptions of Figure 2-3:
When SET key is pressed in the First Menu (Measurement State), the instrument enters
into the Second Menu. The functions except for those in the first menu can be found in this menu,
such as Frequency Setup. Press START key in the Second Menu, you will return to the First
Menu (Measurement State). Press SET key in the Second Menu, you will enter into The Third
Menu, in this menu you can set the sorting limits and nominal value. Press START key in the
third menu, you will return to the First Menu (Measurement State). If SET key is pressed instead
of START key in the third menu, you can also return to the First Menu (Measurement State).
2.3 Functions Setup in the First Menu
Functions in the First Menu (Measurement State) are shown in Figure 2-2.
All functions can be set by the four cursor keys ∧, ∨, ＜and ＞. All functions have
their states. For example, “Measurement Parameter” and “Measurement Frequency” are
functions, while “C/Q”, “R/D”, “C/C”, “R/R” and “D/D” are states of “Measurement Parameter”,
“100 Hz”, “120 Hz”, “1 kHz”, “10 kHz”, “40 kHz” and “100 kHz” are states corresponding to
“Measurement Frequency”.
In the First Menu (Measurement State), there are six function items: “MEAS”, “DISP”,
“LEVEL”, “SPEED”, “RANGE” and “MODE”, which are indicated by six LED lamps
respectively. The LED lamp indicates which function item is to be set, so only one LED lamp is
ON at the same time.
The default states of functions in the First Menu (Measurement State) are as follows:
Function STATE
MEAS: Cp
DISP: DIR
LEVEL: 1.0V
SECOND
MENU
FIRST
MENU
THIRD
MENU

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SPEED: SLOW
RANGE: AUTO
MODE: CONT
Use ＜and ＞keys to select a function, a function is selected when its led lamp is ON.
Then you can use ∧and ∨keys to select the state of this function until the corresponding led
lamp of the state is ON, which means the state is selected.
2.3.1 Measurement Parameter
Parameters to be measured by TH2617 are as follows: Cs, Cp, ESR, EPR.
Units of all parameters are as follows:
C: pF, nF and μF;
R: Ω, kΩand MΩ;
D: no unit.
C and R have different measurement values in different equivalent circuits, and they differ
with change of D. The relation of the two equivalent circuit modes is shown in Table 2.4.2.
C and R may have negative values. When measuring C&D, the negative value of C means
that the component under test has the characteristics of an inductor. In theory, the resistance of R
has the positive value. However, in some cases, value of R may be negative, which is generated
due to excess correction. In order to eliminate the negative value of R, correct corrections are
needed.
Assume that PRis the energy consumed by the equivalent resistor of tested component, and
PCis the energy stored by the equivalent capacitor, then D can be given by
C
R
P
P
D=2-1
According to the equation (2-1), we can use the following equations to calculate D in series
and parallel equivalent circuit models.
S
S
X
R
D=2-2
P
P
R
X
D=2-3
XS is the reactance of the component in series equivalent circuit, while XPis the reactance of
the component in parallel equivalent circuit.
Equation 2-2 and 2-3 show that D has the same sign with that of R, and has no relation with
the sign of Xs or Xp.
2.3.2 Display Mode
TH2617 provides four kinds of display modes:
DIR, △, △% and V/I.
2.3.2.1 DIR Mode

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In DIR mode, the measurement values of the device under test can be read directly from
the instrument.
In DIR mode, the measurement values displayed in Display A have their corresponding
units. The following units are used by the instrument:
pF, nF and μF for C; 1μF =103nF =106pF
Ω, kΩand MΩfor R, 1MΩ=103kΩ=106Ω
Table 2-1 shows that different units are used in different ranges with different resolutions:
Parameter Range Unit Resolution
C < 1.75×10-9F pF 0.0001pF
C 1.75×10-9F ≤C ≤1.75×10-6F nF 0.0001nF
C > 1.75×10-6F μF 0.0001μF
R < 1.75×103ΩΩ0.0001Ω
R ≤1.75×106Ω, ≥1.75×103ΩkΩ0.0001kΩ
R > 1.75×106ΩMΩ0.0001MΩ
Table 2-1 Units and resolutions for different ranges
2.3.2.2 Deviation Measurement
TH2617 provides two types of deviation measurements. They are absolute deviation
measurement and percent deviation measurement. Measurement speed will be reduced because
more time will be used to calculate the deviation.
Nominal Value
Nominal must be set before deviation measurement, because the absolute deviation is the
difference between the measured value of the component and a previously stored nominal value.
Absolute deviation measurement
The difference between the measured value of the device under test and a previously stored
nominal value are displayed. The formula used to calculate the deviation is as follows.
△= Xx – Xn 2–4
Where, Xx: the measured value of the device under test
Xn: the stored nominal value
The unit of the absolute deviation is the same with the value in direct mode, positive or
negative deviations are possible.
Percent deviation measurement
The difference between the measured value of the device under test and a previously stored
nominal value are displayed as a percentage of the nominal value. The formula used to calculate
the percent deviation is as follows.
%100% ×
−
=Δ nnxXXX 2-5
Where, Xx: the measured value of the device under test
Xn: the stored nominal value
In percent deviation measurement the measurement value displays in percentage mode with
the resolution of 0.01%.

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2.3.2.3 Voltage and Current Measurement
Level setup is to set the level value generated by the signal source. Normally, the actual
level across the tested component is always lower than the set value due to the output impedance
of the signal source and the impedance of the tested component.
The actual voltage level Vx across the device under test and the actual current level Ix
through the device under test are given as follows:
Vi
ZxRiZx
Vx ×
+
=ZxRiVi
Ix + =2-6
Where, Vi: the setup voltage level
Zx: the impedance of the device under test
Ri: the output impedance of the signal source
In order to monitor the actual voltage and current level, you can select the V/I display mode.
Then window Display A displays the actual voltage level across the device under test with the
default unit of V; Window Display B displays the actual current level through the device under
test with the default unit of μA.
When measuring the components which are sensitive to the magnitude of signal level, such
as inductor with magnetic core and porcelain capacitor etc., this level monitor function is useful
to find if they are measured and compared under the same level conditions (refer to Chapter III).
2.3.2.4 Display Digits
The maximum number of display digits is five, sometimes is four digits. The table below
describes when four digits and five digits are used by the instrument.
Digits for last measurement First two digits of the
measurement value Digits for this measurement
4 digits < 59 5 digits
5 digits > 62 4 digits
Table 2-2 Display Digits and Measurement Value
Table 2-2 shows the relationship between the measurement values and the display digits.
The instrument will not change the display digits when the first two digits of the measurement
value is in the range of 59 to 62. Thus frequent changes of display digits are avoided when there
is a small change of the measurement value.
2.3.3 Measurement Level
The default measurement level is effective value 1V, when the instrument is switched ON.
TH2617 has three measurement levels for choice: 1V 0.3V 0.1V
An inductor's inductance value may differ widely depending on the current through the
inductor due to the permeability of its core material.
2.3.4 Measurement Speed
TH2617 provides three measurement speeds: fast, medium and slow.

17
2.3.4.1 Measurement Time
The measurement time consists of two main parts: integration time and calculation time.
The sum of integration time and calculation time determined the measurement speed.
Fast speed: approx. 10 times/sec.
Medium speed: approx. 4 times/sec.
Slow speed: approx. 1.3 times/sec.
2.3.4.2 Averaging Rate
The averaging rate can be set in the Second Menu.
We can use the averaging function to acquire the more stable and accurate measurement
value, but the measurement speed will be decreased.
The averaging rate of TH2617 can be programmed from 1 to 99. The default value is 1,
when the instrument is switched on.
For example averaging rate is 4; the measurement values for each measurement are C1, C2,
C3 and C4.
In CONT mode, the instrument outputs the average value CCafter four measurements. The
value CCfinally displayed by the instrument can be given by
CC=(C1+C2+C3+C4)/4
In SINGLE mode, the instrument outputs four averaging values (CS1, CS2, CS3 and CS4) after
the instrument is triggered once. They can be given as follows.
CS1= C1;
CS2= (C1 + C2)/2;
CS3= (C1 +C2 + C3)/3;
CS4= (C1 +C2 + C3 +C4)/4.
2.3.5 Measurement Range
2.3.5.1 Range and the Effective Measuring Range
TH2617 has five ranges: 10Ω, 100Ω,1 kΩ, 10 kΩand 100 kΩ.The measurement range is
selected according to the impedance of the device under test even if measurement parameter is
capacitance or inductance. When measurement range is set to AUTO, the instrument will judge if
the optimum measurement range is selected after each measurement. If the range is the optimum
range, the instrument calculates and displays the measurement value; otherwise the instrument
should adjust the measurement range and measure again. So in AUTO mode, more time will be
used to select the optimum measurement range. We usually discuss the measurement speed when
the measurement range is set manually.
Table 2-3 tells us how to select the optimum range:
RANG NO. RANGE RANGE UP RANGE DOWN
0 100kΩ42kΩ40kΩ
1 10kΩ
2 1kΩ4.2kΩ4kΩ