Yokogawa 202 Field Mounting Rate Totalizer - Manual (Page 36)

Intrinsic Safety Connections 32
8.2 SIMPLE APPARATUS
Devices such as reed switches which can be classed as "simple apparatus", as
defined in the CENELEC standards EN50020, can be connected to the Model
202D without certification.
8.3 NAMUR PROXIMITY SWITCHES
Connection to certified Namur proximity switches is permitted as shown on the
following page with the following maximum input parameters:
Ui = 24V
Ii = 20mA
Pi = 320mW