Casella CEL CEL-424 - Manual (Page 14)

13. Intrinsically Safe Models
Four models in the CEL-420/460 series are available with Intrinsic Safety
approval for use in hazardous areas. Their instrument numbers are
shown in the table.
The operation of each model
is identical to its non-IS counterpart.
The Noise Dosimeter versions use
the standard CEL-6681 microphone
on a 0.75 m cable for personal use
whereas the sound level meter ver-
sions use the standard CEL-425 mi-
crophone adaptor.
The Intrinsically Safe ver-
sions are fitted with a different firmware version but are functionally iden-
tical to the standard products. They may be connected to a personal com-
puter for setup and download of results using the CEL-6702 or 6704
Windows software packages.
Products rating - to EEx ia IIC T4 for use in zones 0, 1 and 2. In-
trinsically Safe Certificate Number - Ex97E2110X tested to EN50020 (this
corresponds to CENELEC apparatus group IIC, North American grouping
Class1).
Approved Power Supply
Only the Duracel® MN1604 alkaline type battery may be used in these
meters (9 V radio battery). The use of any other battery will invalidate the
intrinsically safe certification.
Battery Life
Approximately 30 hours under typical conditions.
Special instructions
The battery must be replaced only in a non-hazardous area.
The instruments must be calibrated in a non-hazardous area fol-
lowing the same instructions as for the standard models.
Any repairs needed for the Intrinsically Safe models must be car-
ried out only by an approved CASELLA CEL service centre following ap-
proved written procedures.
Standard
Model
IS Model Description
CEL-420 CEL-422 Noise Dosimeter
CEL-424 CEL-426 Sound Level
Meter
CEL-460 CEL-462 Noise Dosimeter
CEL-464 CEL-466 Sound Level
Meter
Page 66 - CEL-420/460 Getting Started