Technical data Radar Tank Gauge
88 Installation and Operations Manual
Auxiliary energy
Electrical connection Housing T 12 with separate terminal compartment.
Load HART Minimum load for HART communication: 250
Ω
Cable entry Cable gland: M20x1.5 or Pg13.5
Cable entry: G ½ or ½ NPT
Supply voltage Seepage28
Power consumption Max. 330 mW at 16 V, max. 500 mW at 24 V, max. 600 mW at 30 V.
Current consumption Max. 21 mA (50 mA inrush current).
Power supply For stand alone operation recommended via e.g. Varec RN 221N/Z.
Performance characteristics
Reference operating
conditions
According to OIML R85:
• Temperature = –25…+55 °C (-13…+131 °F)
• Atmospheric pressure
• Relative humidity (air) = 65 % ±15%
• Medium properties: e.g. medium with good reflectivity and calm
surface.
• Tank diameter: signal beam hits the tank wall only at one side.
Note!
No major interference reflections inside the signal beam.
Maximum measured
error
Absolute accuracy: 0.5 mm (2σ value)
Inventory Control Versios: ±3 mm
Proof of accuracy for
custody transfer ver-
sions
The accuracy of each 7500 RTG is established through a calibration
certificate that records the absolute and relative error at 10
equidistant points during the final test. For stilling well measurements
with 7532 RTG, a NMI / PTB calibrated tape with an absolute accuracy
of 0.25 mm is used.
Each 7500 RTG is delivered with the PTB and NMi type approval.
Additional initial factory verifications for custody applications are
available on demand for all 7500 RTG.
Maximum fill speed By the first pass trough of measuring range: 100 mm/min., after it
unlimited.
Non-repeatability 0,3 mm (1/64")
Hysteresis 0.3 mm
Resolution digital: 0.1 mm
analogue: 0.03 % of measuring range
Settling time Typical 15 sec
Long-term drift The long-term drift is within the specified accuracy.
Influence of ambient
temperature
Within the specified accuracy according to OIML R85.
Software reliability The software used in the 7500 RTG fulfills the requirements of OIML
R85. This particularly includes:
• cyclical test of data consistency
• non-volatile memory
•segmented data storage
The 7500 RTG continuously monitor the compliance with accuracy
requirements for custody transfer measurements according to OIML
R85. If the accuracy cannot be maintained, a specific alarm is
generated on the local display and via the digital communication.
