HydroLevelControl

Description

HydroLevelControl is a bundle of hardware and software designed to measure, present and control the level of fluids. Measurement is based on the hydrostatic pressure provided by the fluid above the pressure sensor. The measured pressure value is converted to a requested data format, according to inserted data, like fluid density, reservoir surface, etc. The measured value can be used to activate the visual alarm (blinking LCD display), sound alarm, and two relays. All this can be configured independently.

Take care that this device can be used only on atmospheric pressure. Installation in an over or under pressured environment can permanently damage the sensor and the device! Have to be used only for water, not suitable for petrol, gasoline, alcohol and other organic solvents.

Background

The device has a pressure sensor, actually a pressure transducer, that is powered with 5 VDC. Depending on the pressure, it produces a different voltage on output that is measured and converted to pressure. Based on the fluid density, is possible to calculate the height of the fluid above the sensor. With the known height and the reservoir surface, can be calculated the volume and the mass of the fluid.

Specification

Specification table

Parameter	Value
Hardware
Power	220 VAC or 5 VDC over USB
Sensor type	Pressure transducer, 5 VDC
Sensor range	5 - 15 psi
Sensor offset	0.5 VDC (at 0 pressure) to 4.5 VDC (at maximal pressure)
Inlet size	1/8”-27 NPT
LCD	2.9" with blue background light
Relay	2 independent relays, maximal load 2A at 220VAC
Software
Operation system	Windows 8 and Windows 10
Communication	Serial over USB, TTL on device
Software functions	Configuration and measurement

Hardware

Installation

The device have to be installed on a panel in a hole with dimension 97 x 72mm. All the cables from the AC power, reset switch and sensor need to be connected to the device before mounting. Don't use this device outdoor or in harsh environment. The sensor can be used in wet environment but the LCD not. Also, please take care that a device is powered with 220VAC. Before You mount the device in a hole, connect all the cables and connect the sensor and test the device. Please leave always enough cable to manipulate with the panel by mounting.

Power supply

HydroLevelControl AC power connection and switching connection on the backside.

HydroLevelControl use 100-240VAC for powering. The PSU (Power Supply Unit) of a device provide 5VDC 2A for the MCU (Main Control Unit), LCD, relays, and the rest of the electronics. On the back side of the device is on the outer side the screw connector to put the AC wire. The device don't need high current, so You can use a 1.5mm² wire for power and for switching.

Switching the device On/Off or to restart, can be done with a second screw connector, close to power connector. This can be done with any switch. On this connector is the power line from the main power input to the PSU interrupted over the connector. As You can see on the picture, here is a simple wire the shorts this switch, but is You need a switching, just remove the blue wire and connect Your own switch.

Because the device have a low power composition, You can use it with a 5VDC power over a USB connector on the MCU (USB micro connector). This connector is used to programming the device, but can be also used to power it. Please note, that in a case You use the USB port for powering, You need a 2A 5VDC USB connector that is used for phone charging.

For a higher stability we discourage You to use the USB powering, but if You have no 220VDC, it can be powered over USB, but is less stable and less precise.

Relays

HydroLevelControl relays with connection screws.

Most important part of the device is the controlling function. To be able starting pumps, valves, compressors, and other high load devices, we have integrated two relays. Both of then can be controlled independently. Triggering of relays can be configured in the configuration software to one of the next modes:

1. Off - The relay is not used
2. If above value - The relay will be triggered, if the level rise above the defined value
3. If below value - The relay will be triggered, if the level fall under the defined value

Each relay have his own isolated connection screw. On picture You can see the wiring diagram scheme, where NO mean normally open, CO common and NC normally closed.

The relays can switch up to 10A for a short time, but we recommend to use the relays only to trigger an separate contactor.

LCD and sound alarms

Hidrolevelcontrol LCD alarm video

With the alarm function, You can be always warned if the level of the fluid rise or fall under a predefined levels. Both parameters can be configured individually and independently in a software.

Visual alarm is presented by fast fading of the LCD and return to maximal brightness. This behavior is similar to blinking, but a bit slower. The main goal is to see that an alarming level is reached, even from a bigger distance. Also, if You have multiple installed devices, You can easily see which one is aimed.

Sound alarm is made to have an audio information if the alarming level is reached. The beeper produce a tone with one second, and after it makes an pause from one second, then repeat. Please note that this alarming function can be used only by quiet environment. Also, if You have multiple devices, the sound alarm is not a best solution to distinguish which one is aimed.

The best practice is to set up the visual alarm and the sound alarm together. With this, You will be warned even if You don't look to the device and if You have multiple devices, You will see which one is armed. If You need only to monitor the level, without the alarming function, You can disable this future by the Visual alarm mode and Speaker alarm mode in HydroLevelControl Software.

Sensor

HidroLevelControl sensor 5 and 15 psi

The device use pressure transducer to provide information about a hydrostatic pressure generated by the fluid in a reservoir.

This sensors use 5VDC and have an offset of 0.5VDC. It mean that a pressure transducer have a linear range beginning at the 0 pressure until the declared maximal pressure in a range of 0.5V at zero pressure and 4.5V at maximal pressure.

Inlet of a sensor is made with thread of 1/8" -27 NTP and it need to me mounted in a lowest point of a reservoir. Please note that a sensor will measure the level from the mount point. Highest working temperature is 60 ℃. It can be used to measure water level, don't use it to measure petrol, gasoline oil, and other organic dilutes because it can permanently damage the sensor. Don't overload the sensor. To prevent an overload, always bay a sensor, where the highest possible level of reservoir is about 80% of the sensor measure range.

Sensors with corresponding levels

Sensor (PSI)	Maximal water level (meter)
5	3.5
15	10.5
30	21

HidroLevelControl buzzer and sensor connector

By the mounting in a reservoir take a care not to build siphons. To a achieve this, mount the sensor in a hole that is pointing upwards, so that no air bauble can be closed in a sensor inlet. Closed air in a sensor will produce slower response and lower precision of a sensor. This effect is increased on higher temperature. To prevent overload of the sensor, You can place a valve between the sensor and a reservoir, so that You can close this valve by cleaning the reservoir with over pressured water.

Regardless of the sensor value, it must be connected to the main board. Is done with a with a 4 pin connector (JST XH2.54). By mounting the sensor, leave enough cable length for manipulation by installing and removing the panel from the hole. From the PCB side, the connector is placed close to buzzer, is white colored.

We send the sensor with a soldered connector on a 1m cable. In a case You need a longer cable, You can unsolder the cable and use longer cable. In a real industrial environment, we have successfully installed a dozen systems with more that 10 meters of cable. By this, we used always a 3 wire 1.5mm² cable, don't use cables with smaller diameter.

The pinout of the sensor and the cable is the following:

• Red - +5VDC - is used to powering the sensor, positive pole
• Black - -5VDC - is used to powering the sensor, negative pole
• Green - signal from the sensor to device, the value depending of the applied pressure

If You wish to have a longer cable, always solder "color to color" on a longer cable, taking care not to change the colors, because it can permanently damage the sensor and the device.

• 

  HidroLevelControl 15 PSI sensor with connector

• 

  Sensor and JST XH2.54 4 pin connector

• 

  HidroLevelControl 5 PSI sensor side view

• 

  HidroLevelControl 5 PSI sensor frontal view

• 

  HidroLevelControl 5 PSI sensor backside view

Software

HydroLevelControl software is a program designed to read measured data and configure the hardware. It communicates with a USB to Serial TTL, where the TTL is on the hardware side. The software can be downloaded from this page for free. It supports 16 languages: English, German, French, Spanish, Dutch, Hungarian, Croatian, Slovenian, Serbian (Latin), Czech, Slovakian, Polish, Danish, Swedish, Norwegian, and Finnish.

Main screen of HidroLevelControl
Developer	RAPMAS
Written in	C#
Operating system	Windows
Size	4MB
Licence	Proprietary software
Website	www.rapmas.com/HydroLevelControl/

Installation

The installer can be downloaded online. After starting the install process, You will be asked to choose the language of the installation. Please note that a chosen language will be the default language at the first start of the program. It can be changed later at any time. Executable and the supporting files will be installed (by default) to the Program Files folder, and can be started from the Start menu. Also in the Start menu can be accessed the Uninstaller.

Configuration

Connect the device to the USB port. After starting the program, You can see the main configuration window. It is used to configure a device, read the measured data and to save the configurations into the device, and also file.

In the upper right corner is the Connection group box. You must choose the correct Serial port. After this, You have to click on the Connect button. If the Serial port was correct the Status message will be changed to Connected. Under the Status box can be selected the programming language, after a change, the program will restart automatically in a new language. In the left bottom corner will be presented the measured value with the relay status in a blue box with a white text.

Configuration can be loaded and saved from a device and from a file. To read the initial configuration from the device, click to Load button close to "Load from device". It will connect to the device and read out the configuration. The same can be done with a previously stored file, that contains the configuration parameters. Saving the configuration can be done by clicking on the Save button, close to the destination of saving (Device or File). Please note that a program will check is the input data for any parameter is correct or not. In a case of incorrect value, it will not write the configuration to the device or file.

• Device language is a parameter that changes the information language on the LCD screen. It can be different from Program language.
• Pressure sensor (psi) is a maximal value of the installed pressure sensor. Is engraved on the sensor body (5 psi, 15 psi, etc). Can be only a round number, a decimal number is not allowed.
• Fluid density (kg/m³) can be a round number in kilograms per cubicle meter, without decimal. The density of the clear water is 1000 kg/m³. With a changing of this value, You can fine tune the reading of the device.

• Reservoir surface (dm²) is used to calculate the volume an and weight of the fluids in reservoir. Is presented as round number, without decimal. For example, if the reservoir is round with a diameter of 1.2m, the surface is 3.77 m² and this is 377 dm² . If not needed, just write 1 as value.
• Unit is the metric system in which the device will present the measured value. The device supports next values: mm, cm, dm, m, l (liter), kg, m³, and t (ton).
• LCD brightness (0-100) is a parameter to determinate the background illumination of the LCD. At 0 value is the light off, by 100 is the maximal brightness. In a visual alarm mode, the illumination will move from 0 to 100 and back.
• % mode is made to hide the exact data of a height, volume, mass or any other unit and present it in %. For example, if the reservoir is full at level of 1600 mm, at the 800mm level the device will show 50.00% instead of exact level. To use this mode, You must choose the same unit as in "Unit" parameter above.
• Value at 100% is a round number (decimal not accepted) of the value selected in % mode at maximal value. For example if You wish to calculate with 250 liters as 100%, write 250 and choose l (liter) for % mode. In this case, at volume of 100 liters, the device will show 40%.
• Visual alarm mode defines the behavior of the LCD by reaching a defined value. Is useful if the LCD is mounted in a noisy environment or if You have multiple devices installed, and You need to recognize from a bigger distance, which device show the alarm. It can be set to Off (no action), If above value (trig the visual alarm if the measured value is above the defined) or If below value (trig the visual alarm if the measured value is under the defined).
• Visual alarm value defines a triggering value. It can be a decimal number, like 102.65 . At this value will be the Visual alarm started, if is so configured.
• Speaker alarm mode is same as Visual alarm mode, but is used to trigger the on board speaker. This function is useful in a silent environment to be warned from bigger distance from the measuring place.
• Speaker alarm value have the same function like the Visual alarm value, but for Speaker.
• Relay 1 and Relay 2 mode have the same behavior as Visual alarm mode, but for installed relays.
• Relay 1 and Relay 2 value have same function like the Visual alarm value, but for relays.
• Sensor offset value can define the offset of the different sensors. A pressure transducer works in range from 0 to 5 VDC, but the linear range for measurement is in range of 0.5 VDC (value at 0 pressure) and 4.5 VDC (value at maximal pressure). The difference is 0.5 VDC, and this is a sensor potential offset. The controller measure the potential ot 5VDC in resolution of 1024, so the offset is resolution / working potential * sensor potential offset, practical 1024 / 5VDC * 0.5VDC and this is 102.5, rounded to 103 . Other sensors can have other offset, so read the documentation of the sensor that You use, if is not a sensor provided by us. The delivered sensors have an offset of 103. The offset can be a only a round number like 103, not a decimal.
• Sensor zero value is used to configure a sensor reading if is no load from the water. With a button Read sensor You can automatically receive this value, but You need to empty the reservoir or to remove the sensor fro the water. Wait one minute and after this press the Read sensor button. Wait 10 seconds to data, and it will be filled to the field Sensor zero value. Normal values are close to value of the sensor offset.
• LCD custom text Off/On is a parameter that change the default text (by English language: "Measured value") to a Custom text. If is set to on, the text must be entered before save. Is used to distinguish between multiple installed devices, like "Reservoir 6", or to provide additional information like " Molasses volume". Please note that a text can have maximal 15 alphanumerical characters.