NOSHOK 627 Series Pressure & Level Transmitters - Manual

User Manual
NOSHOK
PRESSURE & LEVEL
TRANSMITTERS
Series 625, 626 and 627
Intrinsically Safe
FM
APPROVED © US
®
(Factory Mutual and Canadian
Standards Association Approved)
CORPORATE HEADQUARTERS
1010 West Bagley Road
Berea, Ohio 44017
440.243.0888
440.243.3472 Fax
E-mail: [email protected]
Web: www.noshok.com
It is important that these transmitters be installed,
operated and maintained in accordance with all NEC
and applicable codes. Also, these products may not
be modified in any way. Failure to adhere to this
requirement will void the IS approval rating.
Model 627 comes standard with a polyurethane
jacketed cable containing a strength member which
allows it to support the transmitter without additional
supports. Also, this cable has a vent tube which
provides an ambient pressure reference. The end of
the vent tube should be protected from moisture.
If moisture finds its way into the transmitter
electronics it could adversely affect the performance
of the product.
For some applications the use of a gortex filter
inserted into the end of the vent tube will be adequate.
In more humid conditions a desiccant cartridge plugged
into the end of the vent tube is recommended. A teflon
jacketed cable is available for applications that are not
compatible with the standard polyurethane material.
Wiring of all the transmitters is based upon a 4 mA
to 20 mA, 2-wire current loop. The DC power supply,
transmitter and receiving instrumentation are wired in
series. The transmitter controls the current in the loop
which is directly proportionate to the measured
pressure.
Maintenance
NOSHOK model 625, 626 and 627 transmitters
require no maintenance. They are calibrated at the
factory using pressure standards traceable to NIST.
However, models 625 and 626 have user accessible
zero and span potentiometers located under the top
cap. These are trimming adjustments with about
±10% adjustment capability. Model 627 is sealed
and does not have any user accessible adjustments.
NUMIS 03-1