NAR300 system for high temperature
Product description
Hauser
11
3.3
Process conditions
3.3.1
Float sensor NAR300 / sensor I/F Ex box
Item
Description
Requirements for
object detection
• Density is at least 0.7 g/cm
3
but less than 1.0 g/cm
3
• Floats in water (if the density is 0.9 g/cm
3
or higher, the viscosity must be at least
1 mPa⋅s. Water
≒
1 mPa⋅s)
• Water-insoluble
• Non-conductive
• Liquid
Operating
temperature
• Ambient temperature: –20 to 100 °C (–4 to 212 °F)
• Measured liquid temperature: 0 to 100 °C (32 to 212 °F)
Requirements for pit
water
• Density is at least 1.0 g/cm
3
but less than 1.13 g/cm
3
(only if the kinematic viscosity
is 1 mm
2
/sec)
• Not frozen
• Conductivity is at least 10 µS/cm (not more than 100 kΩ
･
cm)
• Cannot be used at sea level or in locations that may be penetrated by seawater
Other
• Promptly remove any debris that adheres to the sensor unit.
• Ensure that there is no caked-on mud (dried solids), etc.
• Avoid installation conditions that cause the float sensor to tilt off-balance or change
the draft line.
• Install measures, such as a breakwater, to avoid cross-currents and waves.
1)
Sensitivity will vary with the specific gravity of lower-layer water that differs from the factory-setting
environment, such as when an antifreeze is used.
3.3.2
Connector cable (connection to transmitter NRR261/262 from
sensor I/F Ex box)
Item
Description
Connecting cables
Maximum inductance: 2.3 mH, maximum capacitance: 83 nF
Example: Use of KPEV-S (instrumentation cable)
C = 65 nF/Km, L= 0.65 mH/km
CW/C = 0.083 µF / 65 nF = 1.276 km....1
LW/L = 2.3 mH / 0.65 mH = 3.538 km.....2
Maximum extended cable length: 1.27 km
The smaller of 1 or 2 is the maximum cable length (round down instead of
rounding off)
Operating temperature
–20 to 60 °C (–4 to 140 °F)
