Instruction manual

Technical Data
88 Installation and Operations Manual
11.7 Operating Conditions: Environment
Software
reliability
The software used in the 7500 series RTG fulfills the requirements of OIML
R85.
This particularly includes:
• cyclical test of data consistency
• non-volatile memory
• segmented data storage
The 7500 series RTG continuously monitors 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 (see »Software reliability« on
page 36).
Inventory
control versions
All device types can be delivered as “Inventory Control Versions” with a
reduced accuracy of ±3 mm (under reference conditions). For these versions,
the calibration certificate or custody transfer type approval is not attached.
The “Inventory Control Versions” can be selected by choosing the option “R” in
feature “70 - Custody transfer approvals”, (see page 91).
Ambient temperature
range
Ambient temperature for the transmitter:
• Standard: -40°C to +80°C (-40°F to +176°F)
• For calibration to regulatory standards: -25°C to +55°C
(-30°F to +140°F)
With T
u
< -20 °C and T
u
> +60 °C the operability of the LC-display is
reduced. A weather protection cover should be used for outdoor
operation, if the device is exposed to direct sunlight.
Storage temperature -40°C to +80°C (-40°F to +176°F)
Climate class DIN EN 60068-2-38 (test Z/AD)
Degree of protection • Housing: IP68, NEMA 6P (open housing and removed liquid crystal
display: IP20, NEMA 1)
• Antenna: IP68 (NEMA 6P)
Vibration resistance DIN EN 60068-2-64 / IEC 68-2-64: 20 to 2000 Hz, 1 (m/s
2
)
2
/Hz
Cleaning the antenna Depending on the application, the antenna can get contaminated. The
emission and reception of microwaves can thus eventually be
hindered. The degree of contamination leading to an error depends
on the medium and the reflectivity, mainly determined by the
dielectric constant r.
If the medium tends to cause contamination and deposits, cleaning
on a regular basis is recommended. Care has to be taken not to
damage the antenna in the process of a mechanical or hose-down
cleaning. The material compatibility has to be considered if cleaning
agents are used! The maximum permitted temperature at the flange
should not be exceeded.
Electromagnetic
compatibility (EMC)
• Electromagnetic compatibility in accordance with all relevant
requirements of the EN 61326 series and NAMUR
recommendation EMC (NE21). For details refer to the Declaration
of Conformity. Maximum deviation < 0.5 % of the span.
• A standard installation cable is sufficient if only the analog signal
is used. Use a screened cable when working with a superimposed
communications signal (HART).