Chauvin Arnoux C.A 742 Notice De Fonctionnement page 29

If the test probe is in fact on the phase, the Ph (phase) indica-
tor flashes and the device beeps.
Warning: if the Ph indicator is not flashing, that does not
mean that there is no hazardous voltage on the
outlet.
2.5. USING THE C.A 751 (OPTION)
If you have purchased a C.A 751 2P+T adapter, you can test
for the absence of voltage between the phase and neutral
on an outlet.
Attention: Pairing the C.A 742 with the C.A 751 derates
the combined product to measurement category
II, 250V.
Connect the C.A 751 to the terminals of the C.A 742, then
refer to the operating instructions of the CA.751.
2.6. IP2X PROBE TIPS
Leads with IP2X probe tips are supplied with the device
either as standard (C.A 742 IP2X) or as an option (C.A 742),
depending on the model ordered.
IP2X accessories contribute to safety. These accessories are
mandatory in some countries.
+
600V
CAT IV
230
127
50
24
V
AC
DC
12
29
COM
690 AC
400
750 DC
Ph
Ω
ELV
+ -