The clamp meter supports you in the exact recording of current strength and uses the magnetic field that surrounds the conductor for its indirect measurement of the magnetic field. It is therefore not necessary to disconnect the electric circuit to activate the measuring instrument directly on the cable, because the measurement is contactless.
The current probe – for current strength measurement
The advantages of the testo 770 clamp meter
- Unique hook-on function separates and grabs wires, without using your hands
- Retractable post makes hook release fast and easy
- Inrush (starting) current capture, APO (Auto Power Off), and Min / Max / Hold
Clamp meter testo 770 in comparison
- Clamp meter testo 770-1
- testo 770-1, TRMS clamp meter, including batteries and 1 set of measuring cables
- Order no. 0590 7701
- Voltage: 1 mV to 600 V
- Current: 0.1 to 400 A
- Resistance: 0.1 Ω to 40 MΩ
- Frequency: 0.001 Hz to 10 kHz
- Capacitance: 0.001 μF to 100 μF
- Temperature: N/A
- Measurement category: CAT IV 600 V; CAT III 1000 V
- Clamp meter testo 770-2
- testo 770-2, TRMS clamp meter, including batteries, 1 set of measuring cables and 1 x adapter for type K thermocouples
- Order no. 0590 7702
- Voltage: 1 mV to 600 V
- Current: 0.1 to 400 A
- Resistance: 0.1 Ω to 40 MΩ
- Frequency: 0.001 Hz to 10 kHz
- Capacitance: 0.001 μF to 100 μF
- Temperature: -4 to 932 °F
- Measurement category: CAT IV 600 V; CAT III 1000 V
- Clamp meter testo 770-3
- testo 770-3, TRMS clamp meter, including batteries and 1 set of measuring cables
- Order no. 0590 7703
- Voltage: 1 mV to 600 V
- Current: 0.1 to 600 A
- Resistance: 0.1 Ω to 60 MΩ
- Frequency: 0.001 Hz to 10 kHz
- Capacitance: 0.001 μF to 60000 μF
- Temperature: -4 to 932 °F
- Measurement category: CAT IV 600 V; CAT III 1000 V
Applications:
Precise clamp multimeters for various applications
The pincer-like iron core allows targeted splitting of the busbars. This operating method enables you to measure the current even where you cannot switch off the system temporarily. Using a clamp multimeter makes it possible to record multiple measurement data. These elements allow flexible use and ensure clear data collection.
When using the clamp multimeter, two important points must be kept in mind:
- only one single conductor can be grasped and measured,
- if the clamp encloses an entire cable which contains both conductor and return conductor, only the leakage currents are measured.
The leakage current probe – for even more precision
The leakage current probe is an important measuring instrument for precision work in electronics. In contrast to the classic clamp meter, these diagnostic tools prove to be very sensitive, which means you can also measure extremely small currents with them. High-quality, precise leakage current probes have additional functions, which for instance also test the starting current and measurement data in the μA range. This typically involves a digital clamp meter which you can above all use in the following areas:
- checking the leakage current,
- continuity and resistance testing,
- voltage measurement,
- RMS current measurement.
A leakage current occurs when the current flows via an element which was not intended to be an electrical conductor. The instrument shows the currents for the measurement on the display and makes the user aware of any weaknesses present in the insulation.
In many areas, no shutdown is possible while machines are in operation. However, a leakage current probe enables leakage currents, insulation and the desired current flow to be tested without any problem, even without switching off the equipment for the duration of the measurement. That makes these tools important companions for electricians and for people who are responsible for equipment testing and maintenance. Operation can therefore continue and is not affected by the testing.
High-precision clamp meters from Testo – for greater safety
Testo's modern measuring instruments are characterized by an innovative grab mechanism which is easy to operate. The way the mechanism was designed enables it to grasp the individual conductors properly. This means it ensures reliable, contactless measurement of the current values and other relevant data. Even when the power cables are very tightly packed and only have a very small diameter, you can be sure the clamp meter and leakage current probe will work reliably. The clamp multimeter has a two-line display which is easy to read out and Auto-AC/DC. You have the choice between the following three models:
- testo 770-1 with a fully retractable pincer arm for a high level of flexibility,
- testo 770-2 with additional temperature adapter and measuring values in the μA range,
- testo 770-3 with optimized TRMS method and Bluetooth connection.
For the recording of static magnetic fields
In order to be able to measure direct current too, the DC clamp meter carries out a resistance measurement that is dependent on the magnetic field. This enables static magnetic fields to be recorded, which is necessary because there are no alternating fields present with direct current.
The magneto-resistive resistances which are required for this are fitted in a gap. Their really weak signal needs to be strengthened electronically, so the measuring instruments are equipped with an appropriate energy storage device and function via electric power or a battery. The DC clamp meters are also suitable for alternating current. As well as the measurement data for direct current and alternating current in amperes, the latest measuring instruments provide even more values in other applications, for example direct current and alternating current (DC and AC) in volts. In addition, there are even more measuring functions:
- measurement of resistance (in ohms),
- testing capacitance (in farads),
- measurement of frequency (in hertz).
An aid in many situations
The DC clamp meter – that is the instrument for direct current measurement – is suitable for the maintenance and inspection of electrical systems and small devices. However, using a current probe of this kind not only enables checking of the direct current, but also of the capacitance or resistance. The instrument is important for continuity testing as well. If the objects being tested are difficult to access, the data hold function helps you by making it easier to read out the values.
The movable pincer arm also makes the Testo current probe easy to handle in a difficult environment. Even when power cables are tightly packed in a switching cabinet, it is possible to work safely and reliably. The supplementary function of a leakage current probe enables the measuring tool to help with testing electrical parameters and safeguarding the whole system. You can easily read off the measuring values on the large display and initiate any steps that may be necessary in terms of insulation or system maintenance.