Tank Level Monitor

The 515 LM02 single tank level monitor,  monitors and measures the level of product in a single tank. The instrument uses the 4-20mA signal from a wide range of level sensors, including pressure transmitters, ultrasonic sensors and capacitance probes.

The level monitor provides a 20 point strapping table and product density for level to volume and volume to mass conversions. The instrument can display Volume, Percentage Full and Mass as well as Level. Relay alarms are freely assignable as high or low alarms and an open collector output is provided for programmable level control.
A sub-menu gives full details of alarm status and can offer direct access to change the alarm setpoints. The instrument also has density correction available for pressure level sensors to cater for a deviation in product density.

Calculations

Calculations are based on the analog input signal representing the product level in the tank.

level = (Lmax – Lmin) x A + L min
volume = (Vmax – Vmin) x A* + Vmin
mass = volume x density
where:
A = normalised input signal with
density correction.
A* = A for linear tanks.
A* = f(A) for non-linear tanks.
f(A) = level to volume normalised
strapping table.

Displayed Information

The front panel display shows the current values of the input variables and the results of the calculations. A list of
the variables for this application and their type (total or rate) is shown at the end of this document.
The instrument can be supplied with a real-time clock for data logging of over 1000 entries of the variables as
displayed on the main menu.

Communications

There are two communication ports available as follows:
• RS-232 port
• RS-485 port (optional)
The ports can be used for remote data reading, printouts
and for initial application loading of the instrument.

Isolated Outputs

The opto-isolated outputs can re-transmit any main menu variable. The type of output is determined by the nature of
the assigned variable. Totals are output as pulses and rates are output as 4-20 mA signals. One output is
standard, a second output is available as an option.

Relay Outputs

The relay alarms can be assigned to any of the main menu variables of a rate type. The alarms can be fully configured
including hysteresis. Two relays are standard with an additional two available in the advanced option.

Software Configuration

The instrument can be further tailored to suit specific application needs including units of measurement, custom
tags, second language or access levels. A distributor can configure these requirements before delivery.
Instrument parameters including units of measurement can be programmed in the field, according to the user
access levels assigned to parameters by the distributor.

All set-up parameters and logged data are stored in nonvolatile memory with at least 30 years retention.

For more information on Contrec’s level monitors, please click on the link.