Protech QM1500 Low Cost Digital Multimeter User Manual

Introduction

Thank you for purchasing the Protech QM1500 Low Cost Digital Multimeter. This multimeter is ideal for beginners and for capturing standard measurements including DC & AC voltage, DC current, resistance, transistor, and diode testing. Simply set the rotary switch to the correct position, connect your leads, and you are ready to go.

Please familiarize yourself with the multimeter's functions before use. It is recommended to keep this manual for future reference.

Important Safety Precautions:

• Improper use of this meter can lead to damage, electric shock, injury, or death.
• Always remove the test leads before replacing the battery or fuses.
• Before use, inspect the test leads and the meter for any damage. If damage is found, discontinue use.
• Do not measure voltages exceeding 1000V relative to earth ground.
• Do not exceed the maximum input values specified in the tables on pages 6-7 of this manual.
• Remove batteries if the meter will not be used for an extended period.
• Always turn the function switch to the OFF position when not in use.

Multimeter Overview

The Protech QM1500 features an LCD screen for displaying readings, a function switch for selecting measurement ranges, and input jacks for connecting test leads.

Functions and Input Jacks:

Symbols:

Measurement Procedures

AC/DC Voltage Measurement

1. Insert the black test lead into the COM jack.
2. Insert the red test lead into the VΩmA jack.
3. Set the function switch to the VAC or VDC position. If the voltage is unknown, start with the highest range and decrease it until a satisfactory reading is obtained.
4. Connect the test leads to the circuit being measured. Turn on the device or circuit.
5. Read the voltage on the display.

DC Current Measurement

1. Insert the black test lead into the COM jack.
2. For current measurements:
• Up to 200mA DC: Insert the red test lead into the VΩmA jack.
• 10A DC: Insert the red test lead into the 10A jack.
3. Set the function switch to the desired current position.
4. Remove power from the circuit under test. Open the circuit at the point where current is to be measured.
5. Touch the black test probe to the negative side of the circuit.
6. Touch the red test probe to the positive side of the circuit.
7. Apply power to the circuit.
8. Read the current on the display.

Resistance Measurement

1. Insert the black test lead into the COM jack.
2. Insert the red test lead into the VΩmA jack.
3. Set the function switch to the desired Ω position.
4. If measuring resistance in a circuit, turn off power and discharge all capacitors before connecting the test leads.
5. Read the resistance on the display.

Diode Test

1. Insert the black test lead into the COM jack.
2. Insert the red test lead into the VΩmA jack.
3. Set the function switch to the diode test position (☍).
4. Touch the red test probe to the anode and the black test lead to the cathode of the diode.
5. Reverse the probe polarity and note the reading.
6. Evaluate the diode:
   • If one reading shows a value and the other shows 'OL' (Over Limit), the diode is good.
   • If both readings show 'OL', the diode is open.
   • If both readings are very small or zero, the diode or circuit is shorted.

Transistor hFE Measurement

1. Set the function switch to the hFE position.
2. Determine if the transistor is NPN or PNP.
3. Insert the Emitter, Base, and Collector leads into the corresponding E, B, and C holes in the hFE socket.
4. The meter will display the approximate hFE value at a base current of 10µA and VCE of 2.8V.

Measurement Specifications

DC Voltage

Overload protection: 220VAC for 200mV range, 1000VDC or 750VAC for other ranges.

AC Voltage

Overload Protection: 1000VDC or 750VAC for all ranges. Response: Average, calibrated in RMS of SINE. Frequency Range: 45Hz-450Hz.

DC Current

Overload Protection: 500mA/250V fuse (10A range unfused). Measuring Voltage Drop: 200mV.

Resistance

Maximum Open Circuit Voltage: 2.8V. Overload Protection: 15 seconds maximum, 220V RMS all ranges. Features audible continuity.

Maintenance

Battery Installation

To ensure accurate readings, replace the battery every 6 months if the device is used regularly.

1. Turn the power OFF and disconnect the test leads.
2. Open the rear cover using a screwdriver.
3. Remove the old battery and insert the new battery, observing correct polarity.
4. Replace the battery cover and secure it with a screwdriver.

Replacing Fuses

1. Turn the power OFF and disconnect the test leads.
2. Remove the cover.
3. Gently remove the old fuse and install a new fuse of the correct size and rating (500mA/250V).
4. Replace and secure the cover.

Specifications

• Display: 2000 Count
• Security Class: Cat II 500V
• Basic DCV Accuracy: 0.500%
• DC Voltage: 200mV, 1000V (± 0.5%)
• AC Voltage: 200V, 750V (max input 750V RMS) (± 1.2%)
• DC Current: 2000μA, 20mA, 200mA, 10A (± 1.2%)
• Resistance: 200Ω, 2000Ω, 20kΩ, 200kΩ, 2000kΩ (± 1.2%)
• Measurement Type: Average
• Input Impedance: 1Ω
• Dimensions: 125(H) x 68(W) x 23(D)mm
• Weight: 140g
• Battery Type: 9V (Included)

Box Contents:

• 1 x Multimeter
• 2 x Test leads
• 1 x 9V Battery (Installed)
• 1 x User Manual

Warranty

The product is covered by a 2-year warranty from the date of purchase, covering manufacturing defects. This warranty does not cover damage from neglect, misuse, contamination, alteration, accidents, abnormal operating conditions, or normal wear and tear.

If you suspect your product is defective, cease use and return it with proof of purchase to the place of purchase or distributor for assessment. Distributor contact details are available on the last page of this manual.

If the product is found to be defective, it will be repaired or replaced at no cost. Goods come with guarantees that cannot be excluded under the Australian Consumer Law. Consumers are entitled to a replacement or refund for a major failure and compensation for other reasonably foreseeable loss or damage. Consumers are also entitled to have goods repaired or replaced if they fail to be of acceptable quality and the failure does not amount to a major failure.