D400
Calibration-There is no question the
no 1 issue with a successful calibration of this unit
is proper mounting. The rotation HAS to be within the
correct 90-degree quadrant. But lately we have had some
issues with using the correct power source to calibrate
the unit. The technical specs show that the load voltage
at 20 mA is 8.7 VDC for the standard unit and 9.7 VDC
on IS or EX unit. Therefore, if you connect a 24 VDC
power source only to the unit you will exceed the load
and damage the electronics. Typical loop powered calibrators
such as a Fluke, Alltel, or Druck should be used to
calibrate a D400. You can attempt to save money by providing
a source and mA signal, but one “burnt”
D400 will pay for a good loop calibrator. We use Druck
units and have never had a problem, they are “medium”
priced units, very compact and accurate.
Nema Ratings-As
you may know there are various (too various/many) rating
agencies for products from AZ, from FM, UL, Atex, CSA
to NEMA to GOST to many others. They all have their
hands out wanting you to pay to be approved. We are
frequently asked if our explosion proof unit meets Nema
7, which is a viable US rating agency, that some products
in our industry say they meet-but do they “conform”…??
A quick look at most of our positioner competition shows
that they have a NEMA 4 or 4X “box rating”
and then FM, CSA, Atex. For our hazardous area location
approvals, these are listed in our brochures or IOMs.
Certificates can be provided and are shipped with the
units. |
