Liquipoint T FTW31/32
Liquipoint T sensors are used in conductive liquids (as low as 10 μS/cm) for determining level limits. Depending on the number of measuring points, measuring tasks such as tank overspill protection, pump dry run protection, two-point control of pumps or multiple point level detection can be implemented using a single process connection.
Measurement principle
An alternating voltage exists between the rod probes in an empty tank. As soon as the conductive liquid in the tank creates a connection between the ground probe rod and, for example, the maximum probe rod, a measurable current flows and the Liquipoint T switches. With level limit detection, the Liquipoint T switches back as soon as the liquid clears the maximum probe. With two-point control, the Liquipoint T does not switch back until the MAX and MIN probe is cleared. Using alternating voltage prevents corrosion of the probe rods and electrolytic destruction of the product. The material used for the tank walls is not important for measurement because the system is designed as a closed potential-free circuit between the probe rods and the electronics. There is absolutely no safety hazard if the probe rods are touched during operation.
Features
- Detect multiple level limits with one device
- Flexible instrumentation
- No moving parts in the tank
- No calibration required
Application example
Minicap is designed for point level detection of light bulk solids, with a grain size up to max. 30 mm and a dielectric constant εr ≥ 1.6, e.g. grain products, flour, milk powder, animal feed, cement, chalk or gypsum.
Versions
- Minicap FTC262: with max. 6 m rope probe; for bulk solids
- Relay output (potential-free change-over contact /SPDT) with AC or DC power
- PNP output with three-wire DC power
Probes with integrated electronic insert (compactinstrument version)
The measuring system consists of
- FTW31, with three rods and an electronic insert
- Control units, switches or signal transmitters. e. g. process control systems PLC, relays Probes without integrated electronic insert (separate-instrument version)
The measuring system consists of
- FTW31, FTW32 with two/three rods or ropes
- Nivotester FTW325
- Control units. switches or signal transmitters. e. g. process control systems PLC, elays, etc.
Application example
- Product: liquids as low as 10 μs/cm
- Product temperature: 40 to +212 °F
- Process pressure:-14.5 to +145 psi
Approval
- ATEX II 2G EEx ia
- FTW31
- Rod version
- FTW32
- Rope version