7 Carrying out a measurement
16
7.5.
Power measurement (testo 770-3 only)
For the power measurement, two measurements are carried out at the
same time. The voltage of the measurement object is measured via the
COM
jack,
V
input jack and using two test leads. The current of the
measurement object must be measured using the clamp meter. From these
two factors, the instrument automatically calculates the different types of
power, as well as the power factor.
1. Switch instrument on: set rotary switch to
.
-
The instrument switches on.
-
The instrument is in the mode for power measurement with alternating
current/voltage
2. Enclose the live conductor and centre it in the jaws.
3. Connect test leads: black test lead to black jack, red test lead to red
jack. Then connect test leads to the test object.
4. The instrument displays the active power in w(atts) and the power
factor (PF).
The instrument requires approx. 5 s for the reading to be
displayed. An updated reading is displayed after approx. 5 s.
5. Switch between active power, apparent power, reactive power and
power measurement for direct current/voltage: press
[
]
<1 s.
7.6.
Frequency measurement
The frequency is displayed automatically during an A AC or V AC
measurement.
The following minimum values are necessary for correct
display of
frequency with voltage and/or current measurement:
Voltage: 200 mV
Current: 1.5% of the measuring range
7.7.
Temperature measurement (optional)
(testo 770-2/-3 only)
A thermocouple adapter (0590 0021) is optionally available for measuring
temperature. Before using the thermocouple adapter, please carefully read
through the relevant section relating to the thermocouple adapter in the
documentation. Familiarize yourself with the product before using it. Pay
particular attention to the safety instructions and warning advice in order to
prevent injuries and damage to the product.
In this section, it is assumed that you are familiar with the contents of the
documentation relating to the thermocouple adapter.
Carrying out temperature measurement
✓
A thermocouple is attached to the thermocouple
adapter.
1.
Switch instrument on: set rotary switch to
.
-
The instrument switches on.
-
The instrument is in
AUTO V
mode
2. Connect the thermocouple adapter to the instrument: plug the adapter
into the jack. Ensure correct polarity!
