305
Notes on Approval
Marking
1)
Serial No.
In areas regulated by UL standards, the gas detection transmitter shall be supplied by a Limi-
ted Voltage/Current Circuit, i.e. the open circuit voltage available to the circuit shall not exceed
42.4 V peak and the current available shall be limited to 8 A measured after 1 minute of opera-
tion.
____________________
1) The year of manufacture is indicated by the third letter in the serial number:
T = 2003, U = 2004, W = 2005, X = 2006, Y = 2007, Z = 2008, A = 2009, B = 2010, C = 2011, etc.
Example: Serial No. ARUH-0054: the third letter is U, which means that the unit was manufactured in 2004.
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