Flowserve NRGT26-1 - Manual (Page 5)

5
Explanatory Notes
System description
The compact system NRGT 26- works according to the capacitance measurement principle.
The NRGT 26- is used for signalling different levels in electrically conductive and non-conductive
liquids:
■ Level maintained within the control band defined by two preset limits
The NRGT 26- has a level transmitter integrated in the electrode body which produces a standard
signal of 4 -20 mA. External switchgear is not required.
Function
Designs
The principle of capacitance measurement is applied to determine the level. The electrode rod and
the vessel wall form a capacitor. If the level of the dielectric located between the two capacitor plates
changes, the current which flows through the plates changes proportionally to the level. A dielectric
is defined as an insulating substance, which excludes many liquids such as water. In order to receive
a useful measuring result the measuring rod, which is submerged to varying depths in the liquid,
must be completely insulated. After the calibration of the zero point/measuring range (0 %/00 %)
the level can be read off from a remote display unit. The level measuring range can be changed
during operation.
NRGT 261:
Screwed design ¾" BSP, DIN ISO 228-. Fig. 2
NRGT 261S:
Flanged design for marine application DN 50, PN 40, DIN 2635. Fig. 3
Scope of supply
NRGT 261
 Compact system type NRGT 26-
with joint ring (of stainless steel .430) D 27 x 32 to DIN 7603, bright annealed
 Installation manual
NRGT 261S (for marine applications)
 Compact system type NRGT 26-S with flange DN 50 (2"), PN 40 to DIN 2635
 Installation manual