Hoyt MW38 User manual

DIGITAL MILLIOHM METER
INSTRUCTION MANUAL

INDEX
1. INTRODUCTION.............................
2. SAFETY NOTES.............................
3. FEATURES.....................................
4. SPECIFICATIONS..........................
5. GENERAL.......................................
6. INSTRUMENT LAYOUT..................
7. MEASUREMENT.............................
8. MAINTENANCE..............................
9. FUSE REPLACEMENT...................
PAGE
1
2
3
4
5
6-7
8-12
13
14

-1-
1. INTRODUCTION
NOTE
This meter has been designed and tested According
to CE Safety Requirements for Electronic Measuring
Apparatus, IEC / EN 61010-1 and other safety
standards. Follow all warnings to ensure safe
operation.
WARNING
READ "SAFETY NOTES" (NEXT PAGE) BEFORE
USING THE METER.
CAT IV - Is for measurements performed at the
source of the low voltage installation.
CAT III - Is for measurements performed in the
building installation.
CAT II -
Is for measurement performed on circuits
directly connected to the low voltage
installation.

-2-
2. SAFETY NOTES
●Read the following safety information carefully
Before attempting to operate or service the meter.
● Use the meter only as specied in this manual.
Otherwise, the protection provided by the meter
may be impaired.
●Rated environmental conditions :
(1) Indoor Use.
(2) Installation Category III.
(3) Pollution Degree 2.
(4) Altitude up to 2000 meters.
(5) Relative humidity 80% max.
(6) Ambient temperature 0~40°C.
●Observe the International Electrical Symbols listed
below :
Meter is protected throughout by double
insulation or reinforced insulation.
Warning ! Risk of electric shock.
Caution ! Refer to this manual before using
the meter.

-3-
3. FEATURES
●Protection class: IP65 (Lid closed)
●4-Wire method for mΩ measurement.
●Measures down to 100µΩ (0.1mΩ).
●Maximum resolution of 100µΩ.
●4 Lines × 20 Characters large LCD.
●200 measurement results can be saved in the
memory and recalled on the display.
●Auto power off.
●Data hold function.
●MAX / MIN function.
●Power source: 1.5V "C" battery × 8
●Long battery life and stable power.
●Low battery indication.
●Safety Standard :
EN 61010-1 CAT III 300V
EN 61326-1

-4-
4. SPECIFICATIONS
Measuring ranges
(mΩ)
0~200.0mΩ in steps of 100uΩ
0~2000mΩ in steps of 1mΩ
0~20.00Ω in steps of 10mΩ
0~200.0Ω in steps of 100mΩ
0~2000Ω in steps of 1Ω
Accuracy
±0.8% of reading ±4 digits over the
operating temperature range,
0°C ~ 40°C, with the supplied test
leads
Test current
100mA: 200.0mΩ / 2000mΩ
10mA: 20.00Ω / 200.0Ω
1mA: 2000Ω
Protection fuse 200mA/600V × 1
Operating
temperature 0°C ~ 40°C
Operating humidity 80% Maximum
Dimensions 250(L) × 190(W) × 126(D)mm
Weight
(battery included)
Approx. 2035g
Power source 1.5V "C" battery × 8
Safety standard EN 61010-1 CAT III 300V
EN 61326-1
Accessories Instruction manual Test leads
Shoulder belt Batteries

-5-
5. GENERAL
●Protection fuse:
200mA/600V × 1
●Low Battery Indication :
"LoBAT " message appears on the right lower part
of the display when the battery voltage drops below
accurate operating level.
●Accessories :
Instruction manual
Test leads
Shoulder belt
Batteries
Test leads Shoulder Belt Test leads (optional)

-6-
OFF
200.0mΩ
2000mΩ
20.00Ω
200.0Ω
2000Ω
SEL ESC
TEST/
STOP
ENTER/
SAVE
HOLD
MAX/MIN
DIGITAL
MILLIOHM
METER
CAT III
300V
C2
P2
P1
C1
6. INSTRUMENT LAYOUT
③
②
⑥
⑤⑦ ⑧ ⑨ ⑩
①④
⑪
⑫
⑬
⑭
● Test Leads

-7-
①LCD: 4 Lines × 20 Characters large LCD
②▲Button
③▼Button
④SEL Button
For 3 di󰀨erent functions:
⑴ Date / Time ADJ
⑵ Record display
⑶ Record clear
⑤ESC Button
⑥ENTER / SAVE Button
⑦ MAX / MIN Button
⑧ TEST / STOP Button
⑨ HOLD Button
⑩ Function rotary switch
⑪ C2 Terminal
⑫ P2 Terminal
⑬ P1 Terminal
⑭ C1 Terminal

-8-
7. MEASUREMENT
1.Power On :
Rotate the function switch to keep it from staying in
the "OFF" position.
The system will be auto o󰀨 when it has no operation
after 3 minutes.
2.Before testing, you must make sure that the
resistance under test does not have any voltage.
When the voltage exceeds 5 volts or the probe is
connected to a power supply of more than 5 volts, a
warning message will be displayed.

-9-
3.Select scale range :
There are 5 scale range "200.0mΩ", "2000mΩ",
"20.00Ω" , "200.0Ω" and "2000Ω" could be selected
by rotating the function switch.
2000Ω scale uses the 1mA to test.
200.0Ω & 20.00Ω scales use the 10mA to test.
2000mΩ & 200.0mΩ scales use the 100mA to test.
The screen will display date, time, test current and
maximum resistance.
4.The measurement function
Press "TEST/STOP" button to measure the
resistance value.
Press "MAX/MIN" button to get the max value or
min value in the measurement process.
Press " HOLD " button to keep the value of resistance.
Press " TEST/STOP " button to stop the measurement.

-10-
5.Record saving function
When the measurement is nished, press "SAVE/
ENTER" button to save the result of measurement.
At the same time, the last line will display the
number of record.
The memory can record up to 200 records.
6.Minor function
Press "ESC/SEL" button and hold over 1 second to
enter the minor function.
Use the "UP" and "DOWN" button to move the
function selection cursor, and press "SAVE/ENTER"
to enter the minor function, and press "ESC/SEL"
button to return back to the main page.

-11-
● Date / Time ADJ
Press "ESC/SEL" button to leave the Date/Time
ADJ.
Press "UP" or "DOWN" button to set the correct
number.
Press "TEST/STOP" button to switch to the
next unit of date or time, and go on the required
adjustment.
After all adjustments are completed, press "SAVE/
ENTER" button to conrm and save the date and
time.
Press "ESC/SEL" button to return back to the
minor function menu.

-12-
● RECORD DISPLAY
Press "UP" or "DOWN" button to reach the record
that you want to look up.
Press "ESC/SEL" button to return back to the
minor function menu.
● RECORD CLEAR
Press "SAVE/ENTER" button to clear all records
in the memory.
Press "ESC/SEL" button to return back to the
minor function menu.

-13-
8. MAINTENANCE
Battery replacement :
When " LoBAT " message appears on the right lower
part of the display, change new batteries as follows :
(1) Disconnect the test leads from the instrument and
turn o󰀨 the power.
(2) Unscrew the battery cover and replace with new
batteries(1.5V "C" battery × 8 ).
(3) Re-install the battery cover.
Cleaning and Storage :
WARNING
To avoid electrical shock or damage to the meter,
do not get water inside the case.
Periodically wipe the case with a damp cloth and
detergent. Do not use abrasives or solvents.
If the meter is not used for over 60 days, remove the
batteries for storage.
Batteries
(1.5V "C") × 8
Battery cover
–
+

-14-
9. FUSE REPLACEMENT
Open the meter case, replace with a new fuse
which has the same specication 200mA/600V,
5×20mm.
Due to our policy of constant improvement and development, we
reserve the right to change specications without notice.
Fuse 200mA / 600V
(5 × 20 mm)
W38