-7-
Introduction
The most important factor in assembling your M-2665K Digital Multimeter Kit is good soldering techniques.
Using the proper soldering iron is of prime importance. A small pencil type soldering iron of 25 - 40 watts is
recommended.
The tip of the iron must be kept clean at all times and well tinned.
Safety Procedures
• Wear eye protection when soldering.
• Locate soldering iron in an area where you do not have to go around it or reach over it.
•
Do not hold solder in your mouth.
Solder contains lead and is a toxic substance. Wash your hands
thoroughly after handling solder.
• Be sure that there is adequate ventilation present.
Assemble Components
In all of the following assembly steps, the components must be installed on the top side of the PC board unless
otherwise indicated.
The top legend shows where each component goes.
The leads pass through the
corresponding holes in the board and are soldered on the foil side.
Use only rosin core solder of 63/37 alloy.
DO NOT USE ACID CORE SOLDER!
CONSTRUCTION
Solder
Soldering Iron
Foil
Solder
Soldering Iron
Foil
Component Lead
Soldering Iron
Circuit Board
Foil
Rosin
Soldering iron positioned
incorrectly.
Solder
Gap
Component Lead
Solder
Soldering Iron
Drag
Foil
1.
Solder all components from
the copper foil side only.
Push the soldering iron tip
against both the lead and
the circuit board foil.
2.
Apply a small amount of
solder to the iron tip. This
allows the heat to leave the
iron and onto the foil.
Immediately apply solder to
the opposite side of the
connection, away from the
iron.
Allow the heated
component and the circuit
foil to melt the solder.
1.
Insufficient heat
- the
solder will not flow onto the
lead as shown.
3.
Allow the solder to flow
around the connection.
Then, remove the solder
and the iron and let the
connection cool.
The
solder should have flowed
smoothly and not lump
around the wire lead.
4.
Here is what a good solder
connection looks like.
2.
Insufficient solder
- let the
solder flow over the
connection until it is
covered.
Use just enough
solder to cover the
connection.
3.
Excessive solder
- could
make connections that you
did not intend to between
adjacent foil areas or
terminals.
4.
Solder bridges
- occur
when solder runs between
circuit paths and creates a
short circuit. This is usually
caused by using too much
solder.
To correct this,
simply drag your soldering
iron across the solder
bridge as shown.
What Good Soldering Looks Like
A good solder connection should be bright, shiny,
smooth, and uniformly flowed over all surfaces.
Types of Poor Soldering Connections
-28-
AC Voltage
Range
Resolution
Accuracy
Maximum Input
200mV
100
µ
V
+1.2% of rdg + 2dgt
2V
1mV
+1.2% of rdg + 2dgt
20V
10mV
+1.2% of rdg + 2dgt
AC 750V maximum 50Hz - 400Hz
200V
100mV
+1.2% of rdg + 2dgt
750V
1V
+1.2% of rdg + 2dgt
Resistance
Range
Resolution
Accuracy
Test Current
Input Protection
200
Ω
0.1
Ω
+0.8% of rdg + 2dgt
2k
Ω
1
Ω
+0.8% of rdg + 2dgt
20k
Ω
10
Ω
+0.8% of rdg + 2dgt
Approximately
Protected By
200k
Ω
100
Ω
+0.8% of rdg + 2dgt
1.2mA
PTC
2M
Ω
1k
Ω
+1.0% of rdg + 3dgt
20M
Ω
10k
Ω
+3.0% of rdg + 4dgt
Maximum open circuit voltage: 2.8V
DC Current
Range
Resolution
Accuracy
Protection
200
µ
A
100nA
+0.5% of rdg + 2dgt
2mA
1
µ
A
+0.5% of rdg + 2dgt
Protected by
20mA
10
µ
A
+0.5% of rdg + 2dgt
250V/2A Fuse
200mA
100
µ
A
+0.5% of rdg + 2dgt
20A
10mA
+1.0% of rdg + 3dgt
AC Current
Range
Resolution
Accuracy
Protection
200
µ
A
100nA
+1.2% of rdg + 3dgt
2mA
1
µ
A
+1.2% of rdg + 3dgt
Protected by
20mA
10
µ
A
+1.2% of rdg + 3dgt
250V/2A Fuse
200mA
100
µ
A
+1.2% of rdg + 3dgt
20A
10mA
+3.0% of rdg + 3dgt
Capacitance
Range
Resolution
Accuracy
Protection
2nF
1pF
+3.0% of rdg + 3dgt
2nF
10pF
+3.0% of rdg + 3dgt
200nF
100pF
+3.0% of rdg + 3dgt
Test frequency 400Hz+3.0% Test Voltage 120mV
2
µ
F
1nF
+3.0% of rdg + 3dgt
20
µ
F
10nF
+3.0% of rdg + 3dgt
