Prothermo NMT 538
Hauser Systems & Gauging
21
4.
Operation Principle
4.1
High Accuracy Converter
The Prothermo NMT538 temperature signal converter is designed to fit on existing foreign RTD
average temperature probe to EHauser HART compatible intelligent average
temperature measurement device. The RTD average temp. probe may consist of Cu90, Cu100,
PtCu100, & Pt100 multi-spot and/or multi-resistance element. The Prothermo NMT538 is capable
of converting various RTD resistance input to intrinsically safe IS HART signal output. The liquid
and gas phase average temperature are determined based on liquid level data that is provided
by the Proservo NMS53x or FMR Micro pilot series radar gauge through Tank side monitor
NRF590. Maximum up to 16 individual input can be arranged with either equal or unequal spaced
element intervals are selected. Also the additional WB connection feature allows the NMT 538 to
engage to the foreign water interface measurement probe with average temperature probe like
Weed beacon MW & MWR type, then provide accessibility of auxiliary capacitance converter.
Figure 10:Operating principle of NMT 538
Water bottom
signal out
process connection
NPS ¾
Scanning circuit
Amplifier
Calculation and
HART transmission circuit
Coaxial cable
connection
Gas
Coaxial cable
Oil
(upper layer liquid)
Capacitive probe
(Water bottom sensor)
Flexible tube
(Ex i compatible, sealed)
NMT 538
HART signal out
R
Water
(lower layer liquid)
RTD signal in (up to 16 points)
Clamp connection
4 Operation Principle
