Continuous measurement
The probe continuously detects the dissolved oxygen in the tank or in the pipe.
Measurement and control
LDsDO
Dissolved oxygen is a significant parameter for wastewater. The LDsDO system measures it in mg/l and, according to the set point, controls the activation of blowers that can increase the oxygen concentration in the water.
- Range 0 – 20 mg/l, resolution 0.01
- Fluorescence probe, even in still water
- Automatic temperature compensation
- In by-pass or immersion
0 – 20mg/lMeasuring range
0.01mg/lResolution
−5 / +50°CTemperature
3Probe positions
How it works
Dissolved oxygen control
Blower control
When dissolved oxygen falls below the set point, the controller activates the blowers, which introduce air into the tank through the diffusers and increase the oxygen concentration in the water.
Return to the set point
Once the set value is reached, the controller stops the blowers; the probe continues to analyse the water and reactivates them when the oxygen falls below the set point again.
Applications
Applications
Wastewater
Municipal and industrial wastewater.
Fluorescence
Fluorescence measuring principle
The stainless steel probe directly measures the response of a material excited by a light source. The analysis does not consume oxygen: measurement is therefore possible even in still water, with automatic temperature compensation.
LED light
An LED emits radiation of approximately 475 nm onto the back of the sensing element.
Sensing layer
The surface in contact with the water consists of a thin hydrophobic sol-gel layer containing, isolated from the water, a ruthenium complex.
Fluorescence
As a result of the light excitation, the ruthenium emits fluorescence at approximately 600 nm.
Measurement
The oxygen in contact with the sensor attenuates the fluorescence: the degree of attenuation is correlated with the dissolved oxygen concentration.
The probe →
Technical data
Probe data sheets
| Parameter | Range | Resolution |
|---|---|---|
| Dissolved oxygen | 0 – 20 mg/l | 0.01 mg/l |
| Temperature | −5 / +50 °C | 0.1 °C |
Fluorescence measurement with temperature compensation; probe in by-pass (NPED probe holder) or immersion.
Probe data sheets
Dissolved oxygen probes
| EOLUM | |
|---|---|
| Measuring range | 0 – 20 mg/l |
| Resolution | 0.01 |
| Measuring system | Fluorescence |
| Automatic compensation | Temperature and pressure |
| Operating temperature | −5 / +50 °C |
| Operating pressure | 10 bar |
| Body | Stainless steel |
Installation
Electrode positioning
Electrode positioning is defined according to the characteristics of the installation and of the water to be analysed.
In by-pass
The probes are housed in an NPED probe holder, connected to a water tapping point at the tank outlet and fed with about 30 l/h of sample water. A flow sensor can be added, which stops dosing when there is no flow.
Probe holders →
Immersion
The electrode is immersed directly in the storage tank of the water to be treated, by means of an immersion probe holder.
Probe holders →
Controller
The controller
It acquires the measurement from the probe and drives the dosing pump in proportion to the value detected. It is supplied pre-assembled on a panel, ready for connection.
Colour display
Multicolour backlit display that indicates the different operating states by changing colour. Programming via a single knob.
Four modes
Proportional, ON/OFF, PWM and PID dosing, with delayed dosing start.
Data storage
Permanent data storage and a system log viewable on the display; the internal log can be exported to a USB memory stick for processing with a spreadsheet.
Alarms
Chemical level, no flow, maximum dosing time exceeded, probe failure, out-of-range reading; acoustic or visual signalling via the alarm output.
The dosing pump, with flow rate and back-pressure defined at the time of ordering, is connected to the pulse output (and/or 0-4/20 mA) and operates in proportional or ON/OFF mode. A pre-calibrated injection valve and a magnetic level probe with coaxial foot filter, which stops the pump when the chemical runs out, are supplied as standard.
Colour display
Colour-coded status indication
By changing colour, the controller’s backlit display indicates the different operating states, which can be recognised even from a distance.
Normal operation
Measurement and dosing according to the set parameters.
Stand-by
Controller in stand-by.
Warning
Warning signal, for example the chemical level.
Alarm
Alarm signal, for example from the probe.
Settings from the display
Data sheet
Controller data sheet
Inputs, outputs, control modes and alarms of the controller.
Inputs
- Measuring probe
- Temperature
- Flow sensor
- Chemical level
- Pulse-output water meter or mA signal
Outputs
- 1 proportional dosing pump
- 1 digital output
- 2 proportional 0-4/20 mA outputs
Control
- Proportional
- ON/OFF
- PWM
- PID
- Delayed start
Alarms
- Chemical level
- No flow
- Maximum dosing time
- Probe failure
- Out-of-range reading
Power supply
- 230 VAC
- 12 – 24 VDC
Remote control
System remote control
The controllers can be remotely controlled bidirectionally (read and write) from the web portal, from PC, tablet and smartphone: viewing of measurements, modification of set points, dosing and alarms, receipt of alarms and download of logs. Alternatively, integration into your PLC via Modbus is possible.
Ethernet Optional, one of these
Connection to the web portal via network cable: measurements, set points, dosing and alarms accessible from PC, tablet and smartphone.
Wi-Fi Optional, one of these
Wireless connection to the web portal, with the same functions as the cable connection.
4G Optional, one of these
Connection via the cellular network for installations without a local network, with alarm notification by SMS or e-mail.
Modbus RTU Standard (standard models), optional (PLUS)
Integration into your PLC via serial port.
0-4/20 mA output Standard (PLUS), optional (standard models)
Current signal proportional to the measured value, for remote monitoring or for controlling pumps and other instrumentation.
One communication type at a time: Ethernet, Wi-Fi, 4G or Modbus RTU (built into the standard versions, optional on the PLUS versions). 4/20 mA outputs and meter input standard on the PLUS versions, optional on the standard versions.
The NIMBUS portal
A single account brings together all registered installations, each with its own devices: the web portal, free of charge and with no subscription, can be accessed from PC, Mac, tablet and smartphone and allows every parameter to be both viewed and changed, with an encrypted connection and protected access.
Overview
On a single screen: probe readings, chemical levels, pump activation thresholds and active alarms, with the status of installations and devices (normal, warning, alarm, standby, not connected).
Installation map
Installations appear on an interactive map with their status and open with a click; for each one, the local weather conditions and temperature are also shown.
History and charts
Archive of measurements and alarms, available for consultation at any time with charts and numerical reports exportable in Excel format.
Alarms and notifications
Alarm thresholds for readings, dosing, faulty probe and out-of-range readings, with notification by e-mail or SMS depending on the communication system; a warning is also issued when an installation remains disconnected beyond the set time.
Set points and dosing
Remote modification of the set points, of the dosing pump activation thresholds and of the corresponding hourly flow rate.
Inputs and outputs
Status of relays, pulse outputs, digital inputs and current outputs, with the name assigned to each connection.
Maintenance calendar
Tasks are scheduled by installation or by device and assigned to technicians; a reminder is sent by e-mail two days before the due date. Each task is shown as scheduled, due, overdue or completed.
Team and permissions
The main account has full access and creates the technicians’ accounts, each enabled only for the assigned installations and devices; the last login and activity of each technician are visible.
Reports and activity log
Reports on devices, tasks and technicians, downloadable in PDF or CSV with the customer’s logo; the log keeps the history of operations and disconnections.
Customisation
Logo, main colour and light or dark theme; the tiles on the main screen can be rearranged by dragging them. Two installations can be displayed side by side for comparison.
Guided registration
Each device is added through a guided procedure: the model is recognised automatically and associated with the installation, together with the technician to be contacted.
PLC integration
As an alternative to the portal, the Modbus RTU or TCP/IP port allows integration into the plant supervision system.
Technical advice
Tell us the type of water to be treated and the loads to be controlled: we will propose the most suitable installation and accessories.