Model ST-9933 True RMS Autoranging Digital Multimeter Instruction Manual reedinstruments com
Table of Contents Safety... 3 Features... 4 Specifications...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 info@reedinstruments.com. reedinstruments com 2
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, fixtures, 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, unsoldering, or breaking the circuit. Small amounts of current can be dangerous. Use caution when working above 60VCC or 30VAC RMS. Such voltages are a shock hazard. When using the probes, keep your fingers behind the finger 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 indicates a potentially hazardous situation, which if not avoided, could result in death or serious injury. reedinstruments com 3
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 reedinstruments continued... com 4
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 40.00V 10mV ±1.2% of rdg + 2 digits 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 40.00V 10mV ±0.8% of rdg + 3 digits 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 com 5
DC Current (Auto-ranging for ua and ma) Range Resolution Accuracy 400.0uA 0.1uA 4000uA 1uA 40.00mA 10uA ±1.5% of rdg + 3 digits 400.0mA 100uA 4.000mA 1mA 20A 10mA ±2.5% of rdg + 5 digits 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 4000uA 1uA 40.00mA 10uA ±1.8% of rdg + 5 digits 400.0mA 100uA 4.000mA 1mA 30A 10mA ±3.0% of rdg + 7 digits 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 40.00kΩ 10Ω 400.0kΩ 100Ω ±1.0% of rdg + 2 digits 4.000MΩ 1kΩ 40.00MΩ 10kΩ ±2.0% of rdg + 3 digits Input Protection: 500V DC or 500V AC RMS. reedinstruments com 6
Capacitance (Auto-ranging) Range Resolution Accuracy 40.00nF 10pF ±5.0% of rdg + 7 dgts 400.0nF 0.1nF 4.000uF 1nF ±3.5% of rdg + 5 dgts 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 99.99kHz 0.01Hz 0.5V RMS min. 999.9kHz 0.1Hz 9.999kHz 1Hz ±1.2% of rdg + 3 dgts 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 com 7
Temperature Range Resolution Accuracy -20 C~+1000 C 0.1 C/ C -4 F~+1400 F 0.1 F/ F ±3% of rdg ±2 C/ 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 7 incorrect position 4. F2 fuse is open 6 5. F1 fuse is open 6. Displays the 2 proper input holes location at each measuring range. 5 4 3 7. Disconnect Power displayed at Ohm, Buzzer, Capacitance, Diode and Temperature range. Measure from voltage only. 1 2 reedinstruments com 8
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 connected 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) OFF V CAP Hz % C/ F 10A/mA/µA Measurement(s) Turns the meter off AC/DC Voltage Ohm/Diode/Continuity Capacitance Duty cycle Temperature C/ F AC/DC Current reedinstruments com 9
RANGE button When the meter is first 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. reedinstruments com 10
Input Jacks This meter has four input jacks that are protected against overload to the limits of 20A. During use, connect the Black test lead to the COM jack and the Red test lead as shown below: Function Red lead Connection Input limits DCV/ACV + 1000V DC or 750 AC RMS Ω + 500V DC or AC RMS CONTINUITY/DIODE + 500V DC or AC RMS CAP + 500V DC or AC RMS Hz/% + 500V DC or AC RMS ua/ma + 400mA DC or AC RMS A 10A 10A DC or AC RMS TEMP. Temp. jack 60V DC or 24 AC RMS Voltage Measurement 1. Insert the black test lead into the negative COM terminal and the red test lead into the positive V terminal. 2. Set the function switch to the DCV or ACV position. 3. Connect the test leads to the source or load being measured. 4. Read the voltage measurement on the LCD display. The polarity of the Red connection will be indicated when making a DC measurement. Current Measurement 1. Insert the black test lead into the negative (COM) terminal and the red test lead into the positive (µa, ma) terminal for a maximum measurement of 400mA. For a maximum measurement of 10A, move the red test lead to the positive (A) terminal. 2. Set the function switch to the µa, ma or A position and press the DC/AC button to select the DCA or ACA measurement mode. 3. Connect the test leads to the source or load being measured. 4. Read the voltage measurement on the LCD display. The polarity of the Red connection will be indicated when making a DC measurement. reedinstruments com 11
Resistance Ω Measurement WARNING: To avoid electric shock, disconnect power to the unit under test and discharge all capacitors before taking any resistance measurements. Remove the batteries and unplug the line cords. 1. Insert the black test lead into the negative COM terminal and the red test lead into the positive Ωterminal. 2. Set the function switch to Ω. 3. Make sure the power of the circuit being measured is off. 4. Connect the test leads to the circuit being measured. The range will change automatically, and will be held on the range that will display the measured resistance with the best resolution. 5. The value indicated on the display is the measured value of resistance to the correct decimal point and annunciation indication. Continuity Check WARNING: To avoid electric shock, never measure continuity on circuits or wires that have voltage on them. 1. Insert the black test lead into the negative COM terminal and the red test lead into the positive Ω terminal. 2. Set the function switch to the diode/continuity position. 3. To select continuity test measurement mode, press the MODE button until the (diode/buzzer) symbol appears in the display on the left hand side. In the continuity mode, a buzzer will sound when the resistance of the circuit to be measured is less than approximately 30Ω. reedinstruments com 12
Diode Test WARNING: To avoid electric shock, do not test any diode that has voltage on it. 1. Insert the black test lead into the negative COM terminal and the red test lead into the positive Diode terminal. 2. Set the function switch to the diode/continuity position. 3. Make sure all the power is off. 4. To select the diode test measurement mode, press the MODE button until the (diode/buzzer) symbol appears in the display on the left hand side. Pressing the MODE button again will switch the measurement mode to continuity test. 5. Connect the test leads to the diode being measured. When measuring the forward voltage across diode, a normal diode will indicate 0.4V to 0.7V and the reverse voltage will indicate OL (same as on open condition). For a short-circuited diode, a value near 0 mv will be displayed. Capacitance Measurement WARNING: To avoid electric shock, discharge the capacitor under test before measuring. 1. Insert the black test lead into the negative COM terminal and the red test lead into the positive CAP terminal. The polarity of the lead connection is positive +. 2. Set the function switch to the CAP position. 3. Connect the test leads across the capacitor being measured and be sure that the polarity of the connection is respected. Notes: When checking in-circuit capacitance, be sure that the circuit s power has beened turned off and that all capacitors are fully discharged. In capacitance measurement mode the range control mode is auto-ranging. reedinstruments com 13
Frequency Measurement 1. Insert the black test lead into the negative COM terminal and the red test lead into the positive Hz terminal. 2. Set the function switch to the Hz % position. 3. To select the frequency measurement mode, press the MODE button until the (frequency) Hz symbol appears in the display on the left hand side. Pressing the MODE button again will switch the measurement mode to duty cycle check. 4. Connect the test leads to the circuit being measured. The range will change automatically, and will be held on the range that will display the measured frequency with the best resolution. Duty Cycle Measurement 1. Insert the black test lead into the negative COM terminal and the red test lead into the positive Hz terminal. 2. Set the function switch to the Hz % position. 3. To select the duty cycle measurement mode, press the MODE button until the (duty cycle) % symbol appears in the display on the left hand side. 4. Connect the test leads to the circuit being measured. The range will change automatically, and will be held on the range that will display the measured duty cycle with the best resolution. Temperature Measurement 1. Set the function switch to the C/ F position. 2. Connect the positive sensor to the µa/ma terminal and the negative sensor to the COM terminal. 3. Connect the K-Type test line to the sensor (positive to positive and negative to negative). 4. Connect the test line to the test point beign measured. 5. Read the temperature measurement on the LCD display. reedinstruments continued... com 14
Battery & Fuse Replacement WARNING: To avoid electric shock, disconnect the test leads from any source of voltage before removing the battery or fuse cover. Do not operate your meter with the cover removed. Be sure it is in place and fastened securely. Battery Replacement When the battery level gets low or falls below the operating voltage, the battery warning symbol will appear in the LCD display. 1. Disconnect the test leads from the meter. 2. Open the battery cover by loosening the screws using a Phillips head screwdriver. 3. Insert the battery into battery holder, observing the correct polarity. 4. Put the battery cover back in place. Secure with the two screws. NOTE: If your meter does not work properly, check the fuses and battery to make sure that they are still good and that they are properly inserted. Replacing The Fuses 1. Disconnect the test leads from the meter and any item under test. 2. Open the fuse door by loosening the screw on the door using a Phillips head screwdriver. 3. Remove the old fuse from its holder by gently pulling it out. 4. Install the new fuse into the holder. 5. Always use a fuse of the proper size and value (F1 500mA / 600V fast blow, F2 10A / 600V fast blow). 6. Put the fuse door back in place. Insert the screw and tighten it securely. For service (repairs or calibration) on this or any other REED product or information on other REED products, contact REED Instruments at info@reedinstruments.com. reedinstruments com 15
Notes reedinstruments com 16