User manual

5 Technical data
17
4 Intended use
The instrument may only be used under the conditions and for the purpose
for which it was designed:
• Current measurement, voltage testing in the AC/DC range of
6 to 600 V (testo 755-1) or 6 to 1000 V (testo 755-2), continuity testing /
resistance testing
• Only use the instrument within the specified measuring ranges of the
following overvoltage categories:
- Voltage measurement: CAT IV 600V, CAT III 1000 V
- Current measurement: CAT IV 300V, CAT III 600 V
The instrument must not be used for the following circumstances:
• In potentially explosive atmospheres: the instrument is not explosion-
proof!
• When there is rain or other precipitation: risk of electric shock!
5 Technical data
Voltage testing
Figures correspond to +23 °C ± 5 °C at <80% rel. humidity. Temperature
coefficient: 0.15 x specified accuracy per 1 °C (<18 °C and >28 °C).
Feature Values
Voltage range testo 755-1: 6 - 600 V AC/DC
testo 755-2: 6 - 1000 V AC/DC
Resolution 0.1 V
Tolerance 6 to 49.9 V: ± (1.5% of the display value + 5
digits)
50 to 600 V / 1000 V: ± (1.5% of the display
value + 3 digits)
Frequency range DC voltage, 14 Hz – 400 Hz
Acoustic
signalling
 50 V AC,  120 V DC
Voltage detection Automatic
Polarity detection Automatic
Range detection Automatic
Internal load Approx. 3.5 W at 1000 V
Current Is < 3.5 mA at 1000 V
Operating time 30 s
Recovery time 240 s
Automatic power on > 6 V
Reading memory (HOLD) testo 755-1: 6 - 600 V AC/DC
testo 755-2: 6 - 1000 V AC/DC
Overload indicator testo 755-1: > = 630 V AC/DC, LC display
shows OL
testo 755-2: > = 1050 V AC/DC, LC display
shows OL
Measurement category CAT III 600 V / CAT IV 300 V