Proudly engineered in Switzerland
Density sensor DLO-C3 for Liquids
The DLO-C3 sensor is the OEM version of the proven DLO-M2 series. Like the DLO-M2, this sensor measures the density of liquids using a microelectromechanical system (MEMS). Within this system, the liquid flows through an omega-shaped microchannel known as the Omega-Chip. This tiny silicon tube, thinner than a human hair, is set into vibration, allowing the liquid’s density to be determined from its natural frequency: The higher the density, the lower the natural frequency.
Thanks to its integration into a MEMS system, compact design, and optimized electronics, this sensor is ideal for use in measuring devices, such as portable density meters. The highly precise measurement results are available immediately, enabling continuous monitoring within a system. Since liquid density depends on temperature, an integrated platinum resistor measures the temperature to compensate for this effect automatically.
The collected measurement data is transmitted via a data line using the UART TTL communication format to the overarching system.
Product description
Modbus RTU
- Designed for OEM integration
Inline measurement
- Right in the running process
- Values are output instantaneously
- Quick change of media possible
Density
- Density value
- Max. Measurement error: ±0,5 kg/m³
- Repeatability: ±0,25 kg/m³
Liquids
- Hydrocarbons
- Aqueous media
- and much more – ask us
Concentration packages (option)
- Sugar / water according to ICUMSA (%mass)
- NaCl / water according to Laliberté / Cooper (%mass)
Continuation of concentration packages
- High-fructose corn syrup HFCS42, HFCS55, HFCS90 (%mass / °Brix / °Plato / °Balling)
Continuation of concentration packages
- Ethanol / water according to OIML IST-90
(%mass / %vol@20 °C / ABF@20 °C)
Continuation of concentration packages
- Methanol / water (%mass)
- Ethylene glycol / water in (%mass)
Continuation of concentration packages
- Mineral content in water according to Huber (mg/l)
- Hydrogen peroxide in water (H2O2) (%mass)
Applications
From volume (l) to mass (kg)
If a fuel is pumped from a truck into a tank system, for example, the volume of the tanked liquid is recorded as standard. However, as the density varies depending on the pressure and temperature, it is not possible to make precise statements about the mass. With the DLO-M2 sensor from TrueDyne, you can record the necessary density data during the process and calculate the mass (V-ρ=m).
1. Fuel is pumped from the truck to the tanker. 2. Standardised volumetric measurement in litres. 3. Installed in a bypass line, the density sensor DLO-M2 measures the density directly on the truck. Thanks to the compact design of the sensor, it can also be retrofitted into the process. 4. Together with the volumetric measurement, the density can be used to calculate the mass of the fuel in kilograms, which is then handed over to the customer.
Concentration monitoring
In most cases, the refrigerant in a cooling circuit consists of a mixture of ethylene glycol and water. The optimum concentration is determined depending on the minimum temperature entering the circuit to prevent the liquid from freezing. At the same time, the aim is to keep the water content as high as possible, as this has a positive effect on the thermal conductivity. So how can the concentration of the glycol-water mixture be monitored in the process? With TrueDyne’s DLO-M2 sensor, you collect the data you need to determine the concentration of the medium in the running process.
1. Density sensor with integrated glycol-water concentration calculation. 2. The concentration is output directly as a measured value. 3. Refrigeration plant and preparation of the concentration for cooling industrial applications. 4. Heat exchangers on the roof of factory buildings. Due to the circulation, water can evaporate and the concentration of the refrigerant changes. This is where the DLO-M2 is used for concentration monitoring.
Beer application
Alcohol is produced by fermenting a sugar source with a catalyst, typically yeast or certain bacteria. In the process, the carbohydrates (sugar and starch) are converted into carbon dioxide and ethyl alcohol. This serves as the basis for all alcoholic beverages, regardless of whether they are beer or spirits such as gin and whiskey.
In order to be able to make a statement about the progress of the fermentation process, measurement samples must be taken and analysed regularly. This is exactly where TrueDyne’s DLO-M2 density sensor with integrated concentration determination comes in. Even with small sample volumes, a precise indication of the progress of the fermentation process is possible.
1. Taking a sample from a fermentation tank. 2. Preparation of the sample by degassing and filtering of turbid and suspended matter. 3. Density measurement with integrated concentration calculation of sugar in water. This enables a precise statement about the progress of the fermentation process. 4. Disposal of the test sample. Due to the sensor design and the resulting low sample volume, hardly any rejects are generated.
Quality monitoring
The density of a liquid depends on its composition. If different liquids are mixed, the correct mixing ratio can be checked with density measurements. Take heating oil, for example: according to legal requirements, 7% biodiesel may be added to heating oil. As this is tax-free, it is often used at the limits of legality. With the DLO-M2 density sensor from TrueDyne, you can monitor the quality of the heating oil during the ongoing process.
1. Tanker truck for the delivery of heating oil. 2. The sensor measures the density of the heating oil directly at the transfer point. The data collected on site shows whether the right media are being refuelled in the correct ratio. 3. The product is handed over to the customer. Good quality is guaranteed.
Technology
Overview
The density sensor was designed to measure the density of fluids. This is done with a microelectromechanical system (MEMS) with an omega-shaped microchannel (omega chip) built into an internal bypass.
When a liquid flows through the density sensor, the bypass arrangement creates a pressure gradient across the microchannel, allowing the liquid to reach the omega chip. The liquid influences the physical properties of the excited sensor (resonance frequency and quality), these are digitalised and evaluated in the microcontroller. The measured values can be read out via the serial interface (RS-485, Modbus).
Thus, density measurements in the range 600…1,000 kg/m3 (for further options see product specifications) can be realised at a flow rate of 0…10 l/h. settings.
Omega Chip
The Omega chip, a vibronic microsystem, is the heart of the measurement system and serves to generate the sensor signal in the overall system. The essential component of this microsystem is a silicon tube (microchannel) which is vibrated electrostatically in a vacuum. To compensate for temperature effects, a platinum resistor is integrated, which allows local real-time temperature detection. The Omega chip consists essentially of crystalline silicon and glass.
Measuring principle (omega chip)
Density measurement
For density measurement, the density sensor uses the omega chip. The filled microchannel is set into resonant oscillation and analysed.
The resulting natural frequency of the microchannel depends on the mass and thus on the density of the medium in the microchannel: the greater the medium density, the lower the natural frequency. The natural frequency is thus a function of the density of the medium.
f = natural frequency, E ⋅ I = tube stiffness, ρTube = tube density, ATube = tube cross-section, ρFluid = fluid density, AFluid = fluid cross-section.
Specifications
General
Indicators:
Density and variables derived from it (e.g. standard density, concentration, etc.)
Typical media:
Particulate free (<30 μm) media such as
- Gasoline, diesel, kerosene
- OME (synthetic materials)
- Oils and lubricants
- Water-based media
- Methanol, ethanol, isopropanol
- LPG*
- AdBlue®*
- Glycol mixtures*
Other media can be used after individual clarification. *Optional
Concentration packages:
- Various sugars in water
- Invert sugar in water
- High fructose corn syrup
- Methanol in water
- Ethanol in water
- Salt in water
- Minerals in water
- Hydrogen peroxide in water
- Ethylene glycol in water
- Butane in propane
Note: User-specific concentration packages on request
Performance
Max. measurement deviation:
Density: ±0,5 kg/m³ (option ±[0.2 kg/m³ or 0.0075 x abs (T-25 °C)] kg/m³ if the value is >0.2 kg/m³)
Temperature: ±0,3 °C (option ±0.15 °C or ±[0.005 x abs(T-25 °C)] °C if the value is >0.15 °C)
Repeatability:
Density: ±0,25 kg/m³ (option ±0,1 kg/m³)
Temperature: ±0,1 °C (option ±0,05 °C)
Temperature conditions
Permissible medium temperature:
-40 …..+60 °C
Permissible ambient temperature:
-40 …..+60 °C
Permissible storage temperature:
-40 …..+60 °C
Range of application
Permitted measured density value: 600…1000 kg/m³ (Optionally 0…1200 kg/m³) Permitted viscosity range: 0,3…5 mPa s (Optionally 0,3…50 mPa s)
Permitted medium pressure: 0…20 bar (abs) Burst pressure 80 bar (abs) Permitted particle size: Max. 30 μm
Permitted flow range: 0 to 10 l/h, 0 to 1 l/min for gases
Vibrations: Vibrations (<20 kHz) have no influence on the measuring accuracy due to the high working frequency of the microchannel.
Inlet and outlet runs: Inlet and outlet runs have no influence
on the measuring accuracy.
Ambient conditions
Climate class:
Under clarification
Electromagnetic compatibility:
Prepared for: EMV2014/30/EU (EN 61326-1)
Vibration and shock resistance:
Under clarification
Protection class:
No protection class defined
Material
Wetted parts: • BOROFLOAT® 33 glass
• Silicon
• Epoxy resin
• Stainless steel:
‒ 1.4542 (AISI/SUS 630
• Alternative to stainless steel:
– 2.4605 (Alloy 59)
Dimensions / design
Design, dimensions in mm
Housing:
30 x 66 x 15 mm3 (without cable, cable gland and connection for protective ground)
Weight:
<50 g
Dimensions of measurement channel:
160 x 200 μm (500 nl)
Fluidic interfaces
Fluid interfaces: 2 x M5 threaded holes at a 45° angle to the side and front surface
Electrical interfaces
Level control:
The UART interface is connected directly to the internal microcontroller pins. These are 5 V tolerant I/O pins.
The interface operates with 3.3 V TTL level. Please refer to the STM32L431KCU6 data sheet.
Energy supply:
Maximum current draw 20mA at 5 V, maximum power consumption 100 mW.
Supply: 3.5 V … 5.5 V
Dielectric strength:
The reference potential (GND) is connected to the housing and the ground connection (see product design). There is no galvanic isolation between the
supply circuits, the communication interface and GND.
Certificates and approvals
CE marking:
The density sensor meets the legal
requirements of the EC directives.
TrueDyne Sensors AG confirms the successful testing of the density sensor with the attachment of the CE mark.
directives::
- LVD 2014/35/EU(L96/357)
- RoHS 2011/65/EU(L174/88)
- EMC 2014/30/EU (L96/79) See environmental conditions
Standards:
- EN 61010-1: 2010
- EN 61326-1: 2013
- EN 61326-2-3: 2013
- EN 50581: 2012
Product design
Product design:
1 Density sensor DLO-C3
2 Mounting holes for mechanical fastening
(6 x M3 threaded holes)
3 Fluid interface (2 x M5 threaded holes)
4 PCB incl. plug sockets (back side, see page 10)