ZTW890D High Precision Automatic Digital Multimeter

The ZTW890D series of Chint instruments are battery-driven, high-reliability automatic digital multimeters known for their stable performance. These instruments feature a user-friendly interface with full symbols, a 26mm character height LCD for clear readings, a convenient backlight display, and overload protection functionality. This makes them exceptionally easy to use.

The instrument is versatile and capable of measuring a wide range of parameters including DC voltage, AC true effective value, AC average value, DC current, AC current, resistance, capacitance, continuity, frequency, and diode/on-off automatic identification tests. It also includes a 20-segment analog bar graph for quick visual assessment of measurements and offers a high voltage diode output measurement feature.

One notable advantage of the ZTW890D series is its ability to provide a 1V higher voltage than traditional diode measurement, which simplifies the process of measuring various LEDs. This feature is particularly valuable for maintenance personnel.

Built on a foundation of double-integral A/D conversion, these instruments are ideal tools for use in laboratories, factories, by radio enthusiasts, and in households. They are designed to meet the diverse measurement needs of a wide range of users.

Available at PCBWay: Digital High-precision Automatic Multimeter ZTW890D.

How To Use ZTW980D

Operation Panel

Pointing	Instructions
1	Liquid crystal display
2	Transistor input sockets
3	HOLD/Backlight button
4	SELECT button
5	Function switch
6	mA range input test jack
7	20A current test jack
8	Common jack
9	Voltage, resistance, diode, capacitance, frequency, "+" pole jack
10	Analog range
11	LED Indicator

Voltage measurement using ZTW980D

Insert the black test lead into the COM socket and the red test lead into the V/D/Hz socket, then turn the range switch to the DCV setting, initially selecting the maximum voltage range and gradually reducing it until the highest resolution reading is achieved, ensuring the test leads have secure contact with the test points; the multimeter's LCD screen will display the measured DC voltage value and its polarity, indicating the voltage at the point where the red test lead is connected.

Notice:

1. If "OL" is displayed, it means that the range has been exceeded, and the range switch must be turned to a higher level.
2. The measured voltage should not exceed 1000V DC and 750V AC. When switching functions and ranges, keep the test leads away from the tester's probe.
3. When measuring high voltage, be cautious not to touch the high voltage circuit.

Current measurement using ZTW980D

Insert the black test lead into the COM jack and the red test lead into the mA or 20A jack, then turn the function switch to DC or ACMA/20A; if the measured current is unknown, select the maximum range initially and then gradually reduce it for the highest resolution reading, next, connect the test leads in series with the circuit under test, and the screen will display the measured current value, with the DC current display showing both the current magnitude and polarity at the point connected to the red test lead.

Notice:

1. If "OLC" is displayed, it indicates that the range has been exceeded, and the range switch must be turned to a higher setting.
2. When measuring current, do not exceed 200mA for the mA jack and 20A for the 20A jack (with a test duration of less than 10 seconds). When switching functions and ranges, ensure that the test leads are not in contact with the test point.
3. When measuring high voltage, exercise caution to avoid touching the high voltage circuit.

Resistance measurement using ZTW980D

Insert the black test lead into the COM jack and the red test lead into the V/Q/Hz jack, then turn the range switch to the appropriate resistance range, and connect the two test leads to the resistance being measured.

Notice:

1. If the resistance value exceeds the selected range value, "OL" will be displayed, and the range switch should be turned to a higher setting.
2. When the input terminal is in an open circuit condition, it will display an overload indication.
3. When measuring resistance online, ensure that all power supplies for the circuit under test have been turned off, and all capacitors have been fully discharged. This is only applicable when measuring resistance safely.
4. Do not apply voltage when in the resistance range.
5. When measuring resistance values exceeding 1M, it's normal for the reading to take a few seconds to stabilize; this delay is especially important during high-resistance measurements.

Capacitance measurement using ZTW980D

Insert the black test lead into the COM jack, and the red test lead into the V/Q/Hz jack; then, turn the range switch to the capacitance range, and connect the two test leads across the capacitance being measured.

Notice:

1. If the measured capacitance exceeds the maximum value of the selected range, the display will show "OL".
2. Before testing capacitance, there may still be residual readings displayed on the screen, which is a normal occurrence and will not affect the measurement result.
3. When measuring serious leakage or breakdown capacitance in the large capacitance range, a digital value will be displayed, and it may be unstable.
4. Please ensure the capacitor is fully discharged before testing its capacity to prevent damage to the meter.
5. It is strictly prohibited to apply voltage in this mode.
6. The capacitance setting is an automatic range test, and the measurable range is from 10nF to 60mF.
7. Units: 1mF = 1000uF, 1uF = 1000nF, 1nF = 1000pF.

Frequency measurement using ZTW980D

Connect the test lead or the shielding wire to the COM and V/Q/Hz input terminals, then turn the range switch to the frequency range, and connect the test leads or shielded cables to either the signal source or the load being measured.

Notice:

1. Rotate the dial to the AC750V setting, and press the SELECT key to test AC220V and the mains frequency of AC380V.
2. The frequency setting is an automatic range test, capable of measuring up to kHz.

Transistor hFE measurement using ZTW980D

Set the range switch to HFE, and determine whether the measured transistor is NPN or PNP type; then, insert the emitter, base, and collector into their corresponding jacks.

Diode on-off measurement using ZTW980D

Insert the black test lead into the COM jack and the red test lead into the V/Q/Hz jack (note that the red test lead is marked as '+'). Turn the range switch to the " " position (the default is automatic), then press the 'SELECT' button to switch to the diode testing mode, allowing for automatic recognition of diodes, buzzers, and diode/buzzer combinations. Connect the red test lead to the diode's positive terminal and the black test lead to the negative terminal; the reading will display the approximate value of the forward voltage drop of the diode. Alternatively, connect the test leads to two points within the circuit to be tested, and if the built-in buzzer sounds, it indicates that the resistance value is lower than approximately (50±20)Ω.

NCV/LIVE measurement using ZTW980D

When the dial is set to the NCV measurement function, the meter will emit different intermittent sounds and flash a red alarm light as it detects changes in the electric field strength when brought close to it; to measure a live wire, press the SELECT button to switch modes, insert a red test probe into the VQ jack, ensuring its tip is in close contact with the live wire being measured; the buzzer will emit a continuous sound, and the red alarm light will flash simultaneously.

Data retention in ZTW980D

Press the 'HOLD' button, and the screen will display the 'HOLD' symbol, keeping the current data on the screen; press the button again to remove the 'HOLD' symbol and resume the measurement; for turning on the backlight and closing it, press and hold.

Automtic shutdown in ZTW980D

When the meter is not in use for approximately (15±10) minutes, it will automatically power off and enter a dormant state; to restart the power, turn the dial to the OFF position and then power it on again.

Power on and off in ZTW980D

To turn off the voltage, turn the dial to the OFF position; to turn on the power and cancel the automatic power off function, press and hold the SELECT key, and you will see no 'APO' symbol on the LCD screen.

Backlight display in ZTW980D

Press and hold the HOLD button for 2 seconds to activate the meter's backlight; press and hold the same button again for 2 seconds to turn off the backlight. If there is no action within 12 seconds, the backlight will automatically turn off. To keep the backlight on continuously, press and hold the HOLD button for 3 seconds; if it's already off, press and hold the button for more than 2 seconds to turn it on.

ZTW890D Maintenance

The ZTW890D series of digital multimeters are precision instruments, and users should avoid altering circuits arbitrarily, ensuring attention to waterproof, dustproof, and drop-resistant precautions; avoid storage in high-temperature, high-humidity, flammable, explosive, or strong magnetic field environments. For long-term storage, remove the battery to prevent leakage.

Cleaning the meter's appearance should be done with a damp cloth and mild detergent, avoiding abrasives and strong solvents.

Pay attention to battery usage, and when the screen displays the " " symbol continuously, replace the 2 x 1.5AA batteries using standard AA 1.5V batteries or alkaline batteries for extended use.

Fuse replacement should follow the same method as battery replacement, using a fuse with the same specification and model.