MTS Sensors
Level Plus
®
Liquid-Level Sensors - M-Series Model MR Analog Transmitter
Brief Operation Manual for Safe Use, Document Number: 551409 Revision A, 04/13 (US)
5
Model MR Brief Operation Manual for Safe Use
Basic Wiring, Accessories
Basic Wiring
Accessories
Loop 2 (–)
Loop 2 (+)
Loop 1 (–)
Loop 1 (+)
Earth Ground
Figure 4.
Dual-cavity
housing
Safety barrier examples
Supplier
Type
Uo
Maximum
voltage
Io
Maximum current
(each channel)
Po
Maximum power
(each channel)
Maximum resistance
(each channel)
Number of
channels
STAHL
9001/51-280-091-141
28 Vdc
91 mW
637 mW
350Ω
1
Table 4.
MR safety barrier parameters
Floats
Model MR transmitters should be used with a float having an offset weight and made of stainless steel or Hastelloy C. This allows the float
to stay in contact with the pipe to prevent the buildup of electrostatic charge. For detailed information about floats, refer to the ‘Accessories
Catalog’, MTS part number 551103.
Non-metalic floats with a projected surface area of less than 5,000 mm² should only be used in Zone 0, Gas group IIA such as float part
numbers 201643-2, 201649-2, 201650-2, 201109, 251115 and 251116. All other non-metallic floats offered by MTS such as, 251939,
251119, 251120 and 252999, should not be used in a hazardous area application.
NITROPHYL FLOATS
Float and dimension reference
Projected surface area
Part number
18 mm
(.07 in.) dia.
Magnet
C
L
76 mm
(3 in.)
31 mm
(1.2 in.) dia.
Added weight
for interface floats
2356 mm²
201643-2
201649-2
201650-2
TEFLON FLOATS
Float and dimension reference
Projected surface area
Part number
4635 mm²
201109
251115
251116
61 mm
(2.38 in.) dia.
76 mm
(3 in.)
9 mm
(0.35 in.)
Magnet
Centerline
of Magnet
18 mm
(0.7 in.) dia.
