How to check water lever: 5 low cost technologies

How we can check the level of water or another liquid inside the tank?

There are thousands of ready-to-use solutions available on the market, but you often find products aimed at the industrial sector, featured by high performances, but also by inaccessible costs for less critical market, as the catering world and household devices.

This article introduces 5 of the many types of level sensors

# Measure the water level with ultrasonic sensors

With ultrasonic sensors it is possible to measure the water level inside a tank, exploiting the capacity of this sensors to measure the distance between sensor and water surface.

Usually thess sensors are installed in the high part of the tank, in fixed position.

They consist of an emitter element that generates the ultrasonic signal and a receiver element that receives the emitted wave, something very similar to what happens in the mountains with echo.

The distance between the sensor position and water surface is proportional to the delay between emission and reception of ultrasonic waves.

With ultrasonic sensors it is possible to check with high precision the water level in real time, without any contact between sensor and water.

# Check the water level with reed sensors

Reed sensors are formed by a metallic contact normally opened, situated inside a protected environment, usually formed by a glass cruet filled with inert gas.

The activation of this type of sensor occurs by means of the magnetic field generated from a magnet situated nearby.

Inside the tank that has to be monitored, a float is placed with the magnet inside: when the water level reaches the reed sensor, it is activated by the magnet.

The float is immersed in water, therefore every necessary precaution must be taken in order to satisfy the rules about alimentary use (NSF –

This type of sensor allows to detect the exact condition of overflow or empty tank.

# Check the water level with weight sensors

Using the weight of the water contained in the container, it is possible to activate a switch situated under the tank: this system is very cheap and it is often used for indicate when the water quantity in the tank is about to run out.

# Conductivity level probes

Conductivity level probes are rods made of conductive material, inserted in the tank and exploit the ionic conductivity of the water , in order to notice when the liquid has reached the probe.

We have several electronic solutions designed for level control of tanks, boilers or carbonators that involve the use of one ore more conductivity probes.

The electrical circuit is made up by the measuring electrode and by a second reference electrode: this may be another level probe, or the metal wall of the tank, solution that is usually adopted in brass boiler (or other metal alloy) present in professional coffee machines.

Using two ore more measuring electrodes, each placed at a different depth, it is possible to monitor multiple levels inside the tank.

A very common layout is that with two probes: the first (shallower) is used to check the filling of the tank, while the second (deeper) is used to check when the tank is close to emptying.

Often, in the boilers the deeper probe is also called safety probe, because it is placed just above the level of the resistances and it is used to turn off the heating elements in conditions of lack of water, in order to avoid any damage to the resistors.

Conductivity probes are also widespread in carbonators, tanks into which CO2 is injected under pressure in order to obtain sparkling water.

Probes are necessarily in contact with the liquid, therefore they must be made with materials suitable for food use or appropriately treated (nickel plating or TEA coating).

# The evolution of control with capacitive sensors

sensore livello capacitivo

Capacitive level sensors allow to detect the presence of water or other liquid inside the cases made up with non-conductive materials, without to get in touch with water.

It means that the case must be in plastic, such as a tank or reservoir: when this conditions exists, it is possible to adopt the capacitive technology in order to create a control system (level, overflow or empty) contactless.

Capacitive technology used to detect the presence of water is the same underlying touchscreen systems, although of course fundamentally different sensors and algorithms are used.

Able to simply detect the presence of water at a certain level, the simplest capacitive sensor is composed by two or more sensible elements and by a microcontroller that carries out the necessary analysis to detect the presence of water

Placed in a fixed point outside the removable tank, such as the water tank of coffee machine, they are able to indicate to the control electronics the lack of water, even when between sensor and removable tank is present a layer of air.

In order to work at their best, capacity level sensors must be calibrated in order to suit the specific installation conditions of the particular product.

This is an operation that is normally carried out during the product development phase: the calibration parameters found are set and programmed directly at the time of production of the capacitive sensor, which at this point becomes specific for particular product.

We are developing more advanced capacitive sensors, which allow to detect not only the presence of water in a digital way (water present or absent) but also its actual level, returning an analog value  proportional to the real time quantity of the liquid.

Flexible sensors are now in phase of study, able to be adapted to curved surfaces to which to be glued on, by means of an adhesive specific for this applications.


In this complicated and difficult moment related to the international COVID-19 health emergency, we want to inform you that Gieme is continuing its regular production activity.

Giemme has taken all necessary and possible precautions, in accordance with the orders of the Italian Government, to ensure first of all the safety of our staff and the normal conduct of the activities of all companies.The decrees and restrictive rules currently in force do not prohibit production activities and procurement and shipping of goods.


Smart working: 8 rules for daily smart work

Sometimes you need to work on a customer site and you need to access a specific file, sometimes you need something faster than an email to deliver urgent informations, sometimes you also need to work from home.
Here is our smart working strategy explained in 8 points.

Smart Working Strategy #1: Emails should be accessible always and everywhere, no excuses

Emails should be accessible always and everywhere, no excuses if you want to achieve smart working

Today we cannot depend on a single internet connection line that can be down without any advice, and we cannot leave al our communications archive on an internal server which maintenance is delegated to a contractor: before the switch, when our company’s line was down, we were not able neither to receive or to send emails.

Since 2018 we have decided to move all our mail system on cloud services and our choice has been Microsoft Office365 proposal: it’s a very common choice that allows everyone to access his own account from everywhere and use several platforms (Windows PC, Linux clients, mobile phones).

Smart Working Strategy #2: Internal servers have storage only purposes

Internal servers have storage only purposes

We try to keep internal service maintenance and risks as low as possible, outsourcing as much services as possible: almost everything but file storage is today moved outside our company physical perimeter.
We decide to keep file sharing services on internal servers to be able to deeply manage access availability, speed and permissions.
Several backup systems are in place, using both internal and external destinations.

Smart Working Strategy #3: We must be able to access data from everywhere

OpenVPN allows us to access internal servers from everywhere, beacuse that's the main goal of smart working

That is where our VPN come into play.
We use an OpenVPN solution that allows us to access our local network virtually from any location, using a Windows or Linux PC or even from a smartphone (we suggest Cx File Explorer on Android devices).

Smart Working Strategy #4: Source code is our primary intellectual property

Mercurial and TortoiseHG

We need to be sure that every source code is kept in the safest location, along with its history to be able to reconstruct the life of each development.
That’s why we chose first of all to introduce a reliable version control system to all our development projects: since 2008 we have used Mercurial (hg) to keep track of our changes and to manage change requests, while GIT has a small role in Linux related developments.
Our primary repositories are stored on external servers, installed in big data centers on Italian territory: we can safely access them (via SSH) from everywhere wherever we need to push or pull changes, even we are actively working at Customer’s place.

Smart Working Strategy #5: We all need to keep track of company’s projects and tasks

Redmine helps us to keep track of ongoing tasks

We use Redmine, we use it for several years: I think today there are a lot of better solutions but we stick to it because it fulfills our requirements.
We use this software to keep track of almost every shared task in our company, from production related issues to new components selection and evaluation.
It is deeply customizable, so it can be adapted to several aspects of daily management.

Smart Working Strategy #6: It’s important to share information in a precise and easy way with stakeholders

Trello to manage shared project information

Trello is our choice: we use it to manage project advancement with our customers and with our external engineering partners, using teams and boards templates to keep project up to date and minimizing other forms of communications that could lead to scattered informations.
Emails are still our “source of truth”, but Trello is a much more flexible and modern way to share informations.

Smart Working Strategy #7: Every communication tool has its own response time: mail, instant messaging, calls

We constantly work to reduce wrong utilization of emails, as they are not the correct tools to deliver an information that requires a prompt response by the recipient.
We like the “3 mails then talk” rule (ring the phone if we weren’t able to solve a problem after the third mail) and we support the 8-hours timeframe of an email message (you can wait up to 8 hours to receive a reply to a mail), even if it is very hard to eradicate old habits.

On the other side, we understand that no one is happy to receive one phone call every two minutes.
That’s why we adopt an instant messaging tools to communicate even with people in the same office: it’s fast, it implicitly carries a higher priority sense but it allows the recipient to take his time before replying.

We used several tools during past years, and even if we daily use Skype, Telegram and Whatsapp even with customers and suppliers, today Slack is our primary choice, as it allows 1-on-1 conversations and group chats, and (very important) is available as Android application with very good functionality.

Smart Working Strategy #8: When we need to meet, we propose Zoom

When we need to meet, we propose Zoom for smart working

A lot of time it is not really necessary to meet in person, maybe traveling far from home just to have an one hour meeting.

Today we have plenty of tools that helps us organizing online meetings: we chose Zoom, a video meeting service that allows to create and join 1-on-1 calls or group meetings, with screen sharing, chat, whiteboards and a lot more.

Just a microphone and a webcam and we’re ready to meet.

New European General Data Protection Regulation (GDPR)

On 25 May 2018 the new European legislation on the protection of personal data (GDPR – General Data Protection Regulation, EU Reg. 2016/679) came into force.

Confirming the constant commitment to keep your data protected and to guarantee maximum transparency on the way in which they are treated and kept safe, GIEMME SRL has adapted the Privacy Policy to make it compliant with the new legislation:

We invite you to read the new information and we remind you that you can exercise your rights as per articles 15 and following of EU Regulation 2016/679 such as the right of access, cancellation or simply update the consents by writing to our address

Download here the information on the treatment of personal data for CUSTOMERS

Download here the information on the treatment of personal data for SUPPLIERS

giemme automazione nuovo sito online

New website online

New website of Giemme Srl is online!