The intelligent float level gauge is based on the principle of
force balance. It adopts a new sensing structure on the basis of
the early float level gauge, integrating the sensor and the lever
mechanism into one. It can directly measure the buoyancy that the
float experiences in the liquid, effectively solving the influence
of static pressure. This instrument has outstanding features of
high temperature resistance and high pressure resistance, providing
a good method for measuring the liquid level in high-temperature
and high-pressure containers. Moreover, this instrument has the
advantages of high accuracy, good reliability, convenient
adjustment, wide measurement range, durability, and high
performance-price ratio. It is suitable for continuous measurement
of liquid level, interface, and density in open or pressurized
containers in industrial processes, and is widely used in
industries such as petroleum, chemical engineering, power, food,
water conservancy, metallurgy, thermal power, cement, and
wastewater treatment. This instrument complies with the two-wire
4-20mA transmission protocol and has intrinsically safe type,
flameproof type, liquid crystal indication type, battery type, Hart
type, and various installation forms, providing users with a very
wide range of choices. In addition, the high-quality circuit and
sensing system ensure excellent performance in various application
environments.
Structure and Principle of Intelligent Float Liquid (Density) Level
Meter
1. Structure
The intelligent float liquid (level) gauge consists of a float
bowl, a torque tube, a sensor and a lever, as shown in Figure 1:
2. The float is submerged in the liquid inside the outer float and
is rigidly connected to the torque tube system. Changes in the
position of the liquid inside the outer float, or variations in the
interface level, cause changes in the buoyancy of the float
submerged in the liquid, thereby causing the rotation angle of the
torque tube to change. The higher the liquid level, the greater the
buoyant force on the float, and the smaller the torque force on the
torque tube, and the smaller the rotation angle; conversely, it is
larger. The change in the rotation angle is transmitted to the
sensor that is rigidly connected to the torque tube, causing the
sensor to output a voltage change, which is then amplified and
converted into a 4-20mA current output.
IV. HQFT-D Intelligent Float Level Transmitter Technical Parameters
Measurement Range: 0.3~6m (Special sizes available upon request)
Accuracy Class: 1.0, 0.5 (Special type)
Output Signal: 4~20mA DC two-wire system, with HART protocol
Power Supply: Standard type: 24VDC two-wire 4~20mA (12VDC-32VDC)
Battery type: 3.6V@19AH lithium battery, can be used continuously
for one year
Nominal Pressure: Maximum 4MPa (Special specifications available
upon request)
Ambient Temperature: -40℃~+85℃ (LCD will not be damaged) LCD normal
operation -30℃~+80℃
Medium Temperature: Normal temperature -40℃ ~100℃ (without heat
sink)
High temperature 100℃ ~200℃ (with heat sink)
Ultra-high temperature 200 ~450℃ (with heat sink and jacket device)
Medium Density: Liquid level p≥0.4g/cm3
Interface level p1-p2≥0.1g/cm3
Wetted Parts Material: Measuring chamber is carbon steel or
1Cr18Ni9Ti, the rest is 1Cr18Ni9Ti
Housing Material: Cast aluminum
Connection Flange: Inner float DN30 PN4.0 flange standard DIN2501
Outer float side flange DN50 PN4.0 main flange DN50 PN4.0 flange
standard DIN2501
Special Type: Selected by the user
Cable Interface: Explosion-proof type is 1/2NPT internal thread,
others M20*1.5 internal thread
LCD Display: Main screen liquid level display numerical range:
0-50000 (with decimal point) Sub-screen percentage display retains
one decimal place
Explosion-proof Mark: Intrinsically safe type ia‖CT5
Explosion-proof type d‖BT6
Protection Class: IP65
Load Characteristics: Rlmax=50*(Power supply voltage-12) Ω =600Ω
@24V
| HQFT | Intelligent buoyancy liquid level gauge |
| Installation | C | Side-mounted |
| D | Top-mounted |
| type | D | Top-mounted floating cylinder level gauge |
| C | Side-mounted float level gauge |
| B | Wireless remote transmission float level gauge |
| A | Solar-powered float level gauge |
| Output signal | UB | 4-20MA |
| UI | 485 |
| UJ | HART |
| UK | Switch signal |
| UR | Resistance signal |
| Local instruction format | O | No |
| X | LCD |
| Z | Pointer |
| Main material | 1 | 304 |
| 2 | 316 |
| 3 | 316L |
| 4 | PVC |
| 5 | PP |
| 6 | PTFE |
| Connection | 1 | Carbon steel flange connection |
| 2 | Stainless steel flange connection |
| 3 | Fixation |
| Explosion-proof | O | No |
| D | ExdB II CT-6 |
| I | Exia II CT4-6 |
| Specification | 1 | 0-1000 |
| ... | ......... |
| 10 | 0-5000 |
| Dielectric density | 1 | 0.6g/cm3 |
| 2 | 0.8g/cm3 |
| 3 | 1.0g/cm3 |
| 4 | 1.2g/cm3 |
| 5 | customizable |
| Accuracy | A | 0.20% |
| B | 0.50% |
| C | 1.00% |
| Power supply | Q | 24V |
| R | 220V |
VI. Structure and Installation Diagram of Intelligent Buoyancy
Liquid Level Gauge
On-site installation physical diagram
