REED ST-9933 User manual

reedinstruments
www com
Model ST-9933
True RMS Autoranging
Digital Multimeter
Instruction
Manual

reedinstruments
www com
2
Table of Contents
Safety ............................................................................................ 3
Features......................................................................................... 4
Specications.............................................................................4-8
Technical..................................................................................4-5
Accuracy .................................................................................5-8
Display Description ....................................................................... 8
Operating Instructions..............................................................9-15
Function Switch .......................................................................... 9
Button Functions .................................................................10-11
Voltage Measurement ............................................................... 11
Current Measurement ............................................................... 11
Resistance (Ω) Measurement .................................................... 12
Continuity Check....................................................................... 12
Diode Test................................................................................. 13
Capacitance Measurement ....................................................... 13
Frequency Measurement .......................................................... 14
Duty Cycle Measurement .......................................................... 14
Temperature Measurement ....................................................... 14
Battery & Fuse Replacement..................................................14-15
For service on this or any other REED product or information on other
REED products, contact REED Instruments at [email protected].

reedinstruments
www com
3
Safety
The following safety information must be observed to insure maximum
personal safety during the operation at this meter:
• Do not use the meter if the meter or test leads look damaged, or if you
suspect that the meter is not operating properly.
•
Never ground yourself when taking electrical measurements. Do not
touch exposed metal pipes, outlets, xtures, etc., which might be at
ground potential. Keep your body isolated from ground by using dry
clothing, rubber shoes, rubber mats, or any approved insulating material.
• Turn the power off to the circuit being tested before cutting, unsolder-
ing, or breaking the circuit. Small amounts of current can be dangerous.
• Use caution when working above 60VCC or 30VAC RMS. Such volt-
ages are a shock hazard.
• When using the probes, keep your ngers behind the nger guards on
the probes.
• Measuring voltage which exceeds the limits of the multimeter may
damage the meter and expose the operator to a shock hazard. Always
respect the meter voltage limits as stated on the front of the meter.
• Replacement fuses must be of the correct type and rating.
• The instrument must not be used if any part of it is damaged.
• Warnings and precautions must be read and understood before an
instrument is used. They must be observed during the operation of this
instrument.
Safety Symbols
CAUTION refer to accompanying notes. This symbol indicates
that the operator must refer to an explanation in the Operating
Instructions to avoid personal injury or damage to the meter.
CAUTION risk of electric shock. This WARNING symbol indi-
cates a potentially hazardous situation, which if not avoided,
could result in death or serious injury.

reedinstruments
www com
4
Features
• True RMS measurements
• Temperature function: 1832°F/1000°C
• AC/DC current to 10A
• Auto and manual ranging
• Data Hold and auto shut off
• Resistance to 40MΩ
• Diode check and continuity functions
• Audible and visual safety warnings
• High contrast 4000-count LCD display with backlight
Specifications
Technical
AC/DC Current Range: 20A
AC Voltage Range: 750V
DC Voltage Range: 1000V
Resistance Range: 40MΩ
Continuity Range: 30Ω
Capacitance Range: 100μF
Frequency Range: 9.999MHz
Temperature Range: Max. 1832°F/1000°C
Safety: Designed to Protection Class III requirement of
EN61010-1 over-voltage Category III (CATIII)
Maximum Voltage: 500V RMS (between any terminal & earth ground)
Display: Oversized high contrast 4000 counts
backlight LCD display with dual display
Polarity: Automatic, (-) negative polarity indication
Overrange: “OL” mark indication
Low battery indication: The “BAT” is displayed when the battery voltage
drops below the operating level
continued ...

reedinstruments
www com
5
Measurement rate: 2 times per second, nominal
Auto power off: Meter automatically shuts down after
approx. 30 minutes of inactivity
Operating environment: 0 to 50°C (32 to 122°F)
at < 70% relative humidity
Storage temperature: -20 to 60°C (-4 to 140°F)
at < 80% relative humidity
Power Supply: Standard 9V battery (NEDA 1604, IEC 6F22)
Dimensions: 197 x 88 x 41mm
Weight: 635g (with holster)
Accuracy
Accuracy is given at 18°C to 28°C (65°F to 83°F), less than 70 % RH
DC Voltage (Auto-ranging)
Range Resolution Accuracy
400.0mV 0.1mV ±0.5% of rdg + 2 digits
4.000V 1mV
±1.2% of rdg + 2 digits40.00V 10mV
400.0V 100mV
1000V 1V ±0.8% of rdg + 2 digits
Input Impedance: 50 MΩ & 400 mV range; 8.2 MΩ & other ranges
Maximum Input: 1000 V DC or 1000 V AC RMS.
AC Voltage (Auto-ranging except 400 mV)
Range Resolution Accuracy
400.0mV 0.1mV ±2.0% of rdg + 3 digits
4.000V 1mV
±0.8% of rdg + 3 digits40.00V 10mV
400.0V 100mV
750V 1V ±2.0% of rdg + 4 digits
Input Impedance: 50 MΩ & 400 mV range; 8.2 MΩ & other ranges
Frequency Range: 40 to 400 Hz
Maximum Input: 1000 V DC or 750 V AC RMS.

reedinstruments
www com
6
DC Current (Auto-ranging for uA and mA)
Range Resolution Accuracy
400.0uA 0.1uA
±1.5% of rdg + 3 digits
4000uA 1uA
40.00mA 10uA
400.0mA 100uA
4.000mA 1mA ±2.5% of rdg + 5 digits
20A 10mA
Overload Protection: 0.5A / 600V and 20A / 600V Fuse.
Maximum Input: 400uA DC or 400 mA AC RMS on uA/mA ranges, 20 A
DC or AC RMS on 20 A range.
AC Current (Auto-ranging for uA and mA)
Range Resolution Accuracy
400.0uA 0.1uA
±1.8% of rdg + 5 digits
4000uA 1uA
40.00mA 10uA
400.0mA 100uA
4.000mA 1mA ±3.0% of rdg + 7 digits
30A 10mA
Overload Protection: 0.5A / 1000V and 20A / 600V Fuse.
Frequency Range: 40 to 400 Hz
Maximum Input: 400uA DC or 400 mA AC RMS on uA/mA ranges, 20 A
DC or AC RMS on 20 A range.
Resistance [Ω] (Auto-ranging)
Range Resolution Accuracy
400.0Ω 0.1Ω ±1.2% of rdg + 4 digits
4.000kΩ 1Ω
±1.0% of rdg + 2 digits
40.00kΩ 10Ω
400.0kΩ 100Ω
4.000MΩ 1kΩ
40.00MΩ 10kΩ ±2.0% of rdg + 3 digits
Input Protection: 500V DC or 500V AC RMS.

reedinstruments
www com
7
Capacitance (Auto-ranging)
Range Resolution Accuracy
40.00nF 10pF ±5.0% of rdg + 7 dgts
400.0nF 0.1nF
±3.5% of rdg + 5 dgts4.000uF 1nF
40.00uF 10nF
100.0uF 0.1uF ±5.0% of rdg + 5 dgts
Input Protection: 500V DC or 500V AC RMS.
Frequency (Auto-ranging)
Range Resolution Accuracy Sensitivity
9.999kHz 0.001Hz ±1.2% of rdg + 5 dgts
0.5V RMS min.
99.99kHz 0.01Hz
999.9kHz 0.1Hz
±1.2% of rdg + 3 dgts
9.999kHz 1Hz
99.99kHz 10Hz 0.8V RMS min.
999.9kHz 100Hz 3.5V RMS min.
9.999kHz 1kHz ±1.5% of rdg + 4 dgts 8.0V RMS min.
Sensitivity: RMS min. at >20% and <80% duty cycle
Sensitivity: More than 100 digits at pulse width >2uSec.
Overload Protection: 500V DC or AC RMS.
Duty Cycle
Range Resolution Accuracy
0.1% to 99.9% 0.1% ±1.2% of rdg ± 2 digits
Frequency: 1 Hz to 150 Hz
Sensitivity: 0.5 V RMS min. when F < 10 kHz; 0.8 V RMS min.
when F > 10 kHz; <100 kHz; 3.5 V RMS min.
when F > 100 kHz; < 150 kHz
Pulse Width: > 100 us, < 100 ms
Overload Protection: 500V DC or AC RMS.

reedinstruments
www com
8
Temperature
Range Resolution Accuracy
-20°C~+1000°C 0.1°C/°C ±3% of rdg ±2 °C/°F
-4°F~+1400°F 0.1°F/°F
Sensor: Type K Thermocouple
Overload protection: 60V DC or AC RMS.
* Room temperature (second display): Resolution: 1°C, Accuracy: ±3°C
Diode Test
Test current Resolution Accuracy
0.3mA typical 1 mV ±10% of rdg + 5 digits
Open circuit voltage: 15V DC typical
Overload protection: 500V DC or AC RMS.
Audible continuity
Audible Threshold: Less than 30Ω
Test current: <0.3mA
Overload Protection: 500V DC or AC RMS.
Display Description (Safety Warnings)
1. First LCD display:
Measured values, unit, symbols,
and decimal points are displayed
2. Second LCD display:
Display Room temperature
3. Test leads are in the
incorrect position
4. F2 fuse is open
5. F1 fuse is open
6. Displays the 2 proper input holes
location at each measuring range.
7. “Disconnect Power” displayed at Ohm, Buzzer, Capacitance,
Diode and Temperature range. Measure from voltage only.
1
2
345
7
6

reedinstruments
www com
9
Operating Instructions
Before taking any measurements, read the Safety information at the
beginning of this manual. Always examine the instrument for damage,
defects excessive dirt, grease, etc. Examine the test leads for cracks or
frayed insulation. If any abnormal conditions exist do not attempt to take
any measurements.
To turn the instrument off, turn the range knob from the OFF position to
any measurement range.
• For the best battery life ALWAYS turn the function switch to the OFF
position when the meter is not in use. This meter has Auto OFF that
automatically shuts the meter OFF after 30 minutes of elapsed time.
• On some low AC and DC voltage ranges, with the test leads not con-
nected to a device, the display may show a random, changing reading.
This is normal and is caused by the high-input sensitivity. The reading will
stabilize and give a proper measurement when connected to a circuit.
Mode button
Selects the unit of measurement. The following is a list of the function
selections. Simply turn the the function switch to the appropriate symbol
for the measurement you require.
Position(s) Measurement(s)
OFF Turns the meter off
V AC/DC Voltage
Ohm/Diode/Continuity
CAP Capacitance
Hz % Duty cycle
°C/°F Temperature °C/°F
10A/mA/μA AC/DC Current

reedinstruments
www com
10
RANGE button
When the meter is rst turned on, it automatically goes into AutoRanging.
This automatically selects the best range for the measurements being
made and is generally the best mode for most measurements.
For measurement situations requiring that a range be manually selected,
perform the following:
1. Press the RANGE button. The “Auto Range” display indicator will turn
off, The “Manual Range” display indicator will turn on
2. Press the RANGE button to step through the available ranges until you
select the range you want.
3. Press and hold the RANGE button for 2 seconds to exit the Manual
Ranging mode and return to AutoRanging.
Data Hold button
The HOLD function allows the meter to “freeze” a measurement for later
reference.
1. Press the HOLD button to “freeze” the reading on the indicator. The
“HOLD” message will be appear in the display.
2. Press the HOLD button again to return to normal operation.
The data hold function will be canceled automatically when the function
switch is changed.
Relative Zero button
For convenient readings comparison & offset.