SITRANS LH100, transmitter for hydrostatic level Siemens
Область применения
SITRANS LH100 pressure transmitters are used in the following branches, for example:
- Shipbuilding
- Water/waste water supply
- For use in unpressurized/open vessels and wells
Обзор
The pressure transmitter SITRANS LH100 is a submersible sensor for hydrostatic level measurement.
The pressure transmitter measures the liquid levels in tanks, containers, channels and dams. The SITRANS LH100 pressure transmitters are available for various measuring ranges and with explosion protection as an option.
A junction box and a cable hanger are available as accessories for simple installation.
Дизайн
The pressure transmitter has a built-in ceramic sensor which is equipped with a Wheatstone resistance bridge.
These pressure transmitters are equipped with an electronic circuit fitted together with the sensor in a stainless steel housing. In addition, the connecting cable contains a vent pipe which is equipped with a humidity filter to prevent the build-up of condensation.
The diaphragm is protected against external influences by a protective cap.
The sensor, the electronics and the connecting cable are housed in an enclosure with small dimensions.
The pressure transmitter is temperature-compensated for a wide temperature range.
Функции
SITRANS LH100 pressure transmitter, mode of operation and connection diagram
On one side of the sensor (1), the diaphragm (5) is exposed to the hydrostatic pressure which is proportional to the submersion depth. This pressure is compared with atmospheric pressure. Pressure compensation is carried out using the vent pipe (3) in the connecting cable. The vent pipe is equipped with a humidity filter which prevents the build-up of condensation in the vent pipe.
The hydrostatic pressure of the liquid column acts on the diaphragm of the sensor and transmits the pressure to the Wheatstone resistance bridge in the sensor.
The output voltage of the sensor is applied to the electronic circuit where it is converted into an output current of 4 to 20 mA.
The protective conductor connection/equipotential bonding (4) is connected to the enclosure.
Интеграция
It is generally recommended that the connecting cable of the SITRANS LH100 transmitter is connected to the junction box, which can be ordered separately, and secured with the cable hanger, also available separately. The junction box has to be installed near the measuring point.
If the medium is anything other than water, it is also necessary to check compatibility with the specified materials of the transmitter.
Junction box 7MF1572-8AA, open, schematic diagram
Measuring point setup, generally with junction box 7MF1572-8AA and 7MF1572-8AB cable hanger
Чертеж
SITRANS LH100 pressure transmitter, dimensions in mm (inch)
Junction box, dimensions in mm (inch)
Cable hanger, dimensions in mm (inch)
Особенности
- Compact design
- Simple installation
- Small error in measurement (0.3 %)
- Degree of protection IP68
Технические данные
Pressure transmitter SITRANS LH100 (submersible sensor) | |
Mode of operation | |
Measuring principle | piezo-resistive |
Input | |
Measured variable | Hydrostatic level |
Measuring range | Max. permissible operating pressure |
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Output | |
Output signal | 4 ... 20 mA |
Measuring accuracy | According to IEC 60770-1 |
Error in measurement at limit setting including hysteresis and reproducibility | |
Measuring range | |
| 0.5% of full-scale value (typical) |
| 0.3% of full-scale value (typical) |
Influence of the ambient temperature | |
Measuring range | Zero and span |
| 0.45 %/10 K of full-scale value |
| 0.45 %/10 K of full-scale value |
| 0.3 %/10 K of full-scale value |
Long-term stability | |
Measuring range | Zero and span |
| 0.4% of full-scale value/year |
| 0.25% of full-scale value/year |
| 0.2 % of full-scale value/year |
Rated conditions | |
Ambient conditions | |
| -10 ... +80 °C (14 ... 176 °F) |
| -40 ... +80 °C (-40 ... +176 °F) |
Degree of protection according to IEC 60529 | IP68 |
Design | |
Weight | |
| ≈ 0.2 kg ( ≈ 0.44 lb) |
| 0.025 kg/m (≈ 0.015 lb/ft) |
Electrical connection | Cable with 3 conductors, vent pipe and integrated humidity filter |
Material | |
| Al2O3 ceramic, 96% |
| Stainless steel, mat. no. 1.4404/316L |
| FPM (standard) EPDM (optional) |
| PE-HD (standard) PE-LD (in the case of versions with EPDM seal, suitable for drinking water applications) |
Auxiliary power | |
Terminal voltage on pressure transmitter UB | 10 ... 33 V DC 10 ... 30 V DC for transmitter with intrinsic safety explosion protection |
Certificates and approvals | |
Drinking water approval (ACS) | applied for |
Drinking water approval (WRAS) | 1403525 |
EAC | № TC RU C-DE.ГБ05.В.00732 |
Underwriters Laboratories (UL) | 2014-11-17 - E344532 |
The transmitter is not subject to the pressure equipment directive (PED 97/23/EC) | |
Explosion protection | |
| IECEx SEV 14.0003 |
| II 1 G Ex ia IIC T4 Ga |
Junction box | |
Application | for connecting the transmitter cable |
Design | |
Weight | 0.2 kg (0.44 lb) |
Electrical connection | 2 x 3-way (28 to 18 AWG) |
Cable entry | 2 x Pg 9 |
Enclosure material | polycarbonate |
Vent pipe for atmospheric pressure | |
Screw for cable strength cord | |
Rated conditions | |
Degree of protection according to IEC 60529 | IP65 |
Cable hanger | |
Application | for mounting the transmitter |
Design | |
Weight | 0.16 kg (0.35 lb) |
Material | Galvanized steel, polyamide |
Дальнейшая информация
Determination of the measuring range for media with a density of ≠ 1000 kg/m3 (medium ≠ water)
Calculation of the measuring range:
p = ρ x g x H
with:
ρ = density of medium
g = local acceleration due to gravity
H = maximum level
Example:
Medium: Diesel fuel, ρ = 850 kg/m3
Acceleration due to gravity: 9.81 m/s2
Start-of-scale: 0 m
Maximum level: 6.0 m
Cable length: 10 m
Calculation:
p = 850 kg/m3 x 9.81 m/s2 x 6.0 m
p = 50 031 N/m2
p = 500 mbar
Transmitter to be ordered:
7MF1572-1FA11
Plus, if required, junction box 7MF1572-8AA and cable hanger 7MF1572-8AB
Ответ от производителя может занять до 5 дней и более.
