Tonghui TH2512 Instruction Manual

TH2512

DC Milliohmmeter

Instruction Manual

arranty ..................................................................................................................................................... 3

W

Safety Precautions.................................................................................................................................... 4

Chapter 1. Introduction ........................................................................................................................5

1.1 Unpacking and Inspection .......................................................................................................5

1.2 Product Overview.................................................................................................................... 5

1.3 Controls and Indicators............................................................................................................ 6

1.3.1 Front Panel Controls and Indicators....................................................................... 6

1.3.2 Rear Panel Controls and Connectors .................................................................... 7

1.4 Installation ............................................................................................................................... 7

1.4.1 Dimensions ................................................................................................................7

1.4.2 Power Requirements ................................................................................................ 7

1.4.3 Safety Inspection....................................................................................................... 8

1.5 Specifications........................................................................................................................... 8

1.5.1 Resistance Range:.................................................................................................... 8

1.5.2 Measurement Rate ...................................................................................................8

1.5.3 Trigger......................................................................................................................... 8

1.5.4 Ranging ......................................................................................................................8

1.5.5 Zeroing........................................................................................................................ 9

1.5.6 Comparator ................................................................................................................ 9

1.5.7 Display ........................................................................................................................ 9

1.5.8 Beep Alarm ................................................................................................................9

1.5.9 Interfaces.................................................................................................................... 9

1.5.10 Unknown Connector ................................................................................................. 9

1.5.11 Dimensions ................................................................................................................9

1.5.12 Weight......................................................................................................................... 9

1.5.13 Environmental.......................................................................................................... 10

1.5.14 Power........................................................................................................................ 10

Chapter 2. Operatio

n.......................................................................................................................... 11

2.1 Startup.................................................................................................................................... 11

2.2 Display................................................................................................................................... 11

2.3 SPEED................................................................................................................................... 11

2.4 Measurement mode................................................................................................................ 11

2.5 Comparator Function............................................................................................................. 12

2.6 ZERO..................................................................................................................................... 13

2.7 RANGE ................................................................................................................................. 13

2.8 Beeper.................................................................................................................................... 14

Chapter 3. Handler Interface............................................................................................................. 15

3.1 Handler Interface................................................................................................................... 15

2

Warranty

This Tonghui instrument product is warranted against defects in material and workmanship for
a period of one year from the date of shipment. During the warranty period, Tonghui 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 Tonghui.

The foregoing warranty shall not apply to defects resulting from improper or inadequate
maintenance by Buyer, Buyer-supplied software or interfacing, unauthorized modifications for
the product, or improper site preparation or maintenance.

No other warranty is expressed or implied. Tonghui specifically disclaims the implied
warranties of merchantability and fitness for a particular purpose.

Tonghui shall not be liable for any direct, indirect, special or consequential damages, whether
based on contact, tort, or any other legal theory.

3

Safety Precautions

CAUTION

The TH2512 DC Milliohmmeter is a low voltage instrument and provides no more
than 1A DC output to the device under test (DUT). Some devices tested
(especially capacitors) can store charge and may cause a hazard if not
discharged properly. Follow these safety instructions.

1. Operate the TH2512 unit with its chassis connected to earth ground. The instrument is
shipped with a three-prong power cord to provide this connection to ground. This power
cord should only be plugged in to a receptacle that provides earth ground.

2. Plug the Kelvin low ohm clip leads into the unknown terminal.

3. Before touching the test lead wires or output terminals make sure any capacitive device
has been fully discharged.

4. In the case of an emergency, turn OFF the POWER switch using a “hot stick” and
disconnect the AC power cord from the wall. Do not touch the TH2512 instrument.

4

Chapter 1. Introduction

1.1 Unpacking and Inspection

Inspect the shipping carton before opening. If damaged, contact the carrier agent
immediately. Inspect the TH2512 DC Milliohmmeter instrument for any damage. If the
instrument appears damaged or fails to meet specifications notify Tonghui (refer to
instruction manual front cover) or its local representative. Retain the original shipping carton
and packing material for future use such as returning the instrument for recalibration or
service.

1.2 Product Overview

The TH2512 DC Milliohmmeter is a precision low resistance meter for production or
laboratory testing of individual components, materials, printed circuit boards and other
resistive items. The TH2512 instrument provides nine measurement ranges from 20m to
2M over seven current ranges from 1μA to 1A. The basic measurement accuracy is

0.05%. Measurement rate is selectable (Slow or Fast) with rates up to 10 measurements
per second. Automatic or Hold Range can also be selected. Measurements can be made
continuously or triggered. The Handler interface is standard and the IEEE-488/RS232
interface is optional equipment on the TH2512 instrument. The effects of series resistance
in the test leads can be zeroed with the short correction function. The TH2512 instrument is
equipped with Pass/Fail bins. High and low limits set in the Comparator function display the
measured result as a percent. Compare results can be indicated on the front panel as well.
Four-terminal Kelvin connection to the device under test is obtained through the unknown
terminal on the front panel.

TH2512 illiohmmeter DC M

REMOTE

ON

POWER

ON

OFF

FUNCTION

R

mΩ

Ω

UNKNOWN

MΩkΩ

ON ON

CONT

ON ON

TRIG

%

SLOWFAST

SORT

ZERO

DISP

SPEED

ON

SETUP

AUTO

RANGE

COMPARATOR INDICATION

LOW

TONGHUI ELECTRONIC

PASS

CURSOR

HIGH

Figure 1-1: TH2512 DC Milliohmmeter

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