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Product information

  • Device: opTim
  • Category: Speed of Sound Measurement Unit
  • Datasheet: opTim ver 2.0

opTim ver 2.0
Speed of Sound Measurement Unit

OPTIM 2.0 is a very versatile device for precise measurement of speed of sound in gases (air, CO2, N, CH4, other gases and mixtures) as well as other gas properties like: temperature, attenuation, pressure, concentration. All in one low power and compact size device.

OPTIM 2.0 is ready for laboratory: fully configurable manual/automatic modes, raw data upload, RF signal inspection and for industrial purpose: several automatic measurement modes, continuous operation, all measurement results and data from external sensors in one frame.

OPTIM-2.0 is an ultrasonic measuring device designed for precise measurements of the speed of sound in gases. The measurement of the speed of sound is performed using the method of measuring the time of flight of the ultrasonic wave in a system of two transducers (transmission system) placed at a fixed distance from each other, between which the gas is located. The system uses ultrasonic transducers that generate a short 1MHz pulse. Specially selected parameters of the transducer front allow it to be used in an atmosphere of explosive gases (Ex zone) and at the same time ensure optimal parameters for reflecting and receiving the ultrasonic wave in the measuring chamber. The low-noise receiving path of the device with a wide range of adjustable gain ensures obtaining the correct signal level in a wide range of applications (gases with different attenuation coefficient, chambers with different measuring distances). A precise, high-resolution timing system with an adjustable level comparator allows you to achieve stable and repeatable measurements. Advanced algorithms for automatic signal conditioning simplify the preparation of the device for measurement and ensure correct operation despite rapid and large changes in gas parameters during measurements. In addition to measuring the speed of sound, OPTIM-2.0 also allows the integration of many additional sensors that allow the measurement of additional physical parameters used in the assessment of the quality of the gas (or gas mixture). The device allows, among other things, to connect two Pt1000 temperature sensors, two NDIR concentration sensors and one other sensor (e.g. pressure) equipped with a 0-20mA current output or a 0-5V voltage output. OPTIM-2.0 collects and processes all measurement data and makes them available to the master device via the RS232 interface. Communication takes place using a simple and transparent protocol based on short commands written in ASCII code, which allows for easy integration with various devices and measurement systems. Thanks to the extensive possibilities of measurement modes, the device can be successfully used for laboratory measurements, where you can use all the possibilities of manual and automatic operation of the device, as well as for industrial applications requiring maintenance-free and automatic operation in specific configurations


Speed of Sound measurements in gases (laboratory, industrial)

Gas quality measurements

Ultrasound attenuation measurements

Ultrasound ToF and/or thickness measurments with very high resolution

Features & Technical data

Very precise ToF measurement (50ps resolution). Wide range of SoS measurement (up to 1000m/s). hrough transmission mode, 1MHz transducers. Hardware peak detector for amplitude measurements Easy to use ASCII protocol over RS232. RF signal output for diagnostic.

Automatic signal conditioning algorithm

Several configurable meas. modes

Store up to 100 settings sets

Self-hardware diagnostic.

Speed of Sound measurement. Measurement principle Time of Flight measurement SoS range 100...1000 [m/s] ToF modes of operation 1st reflection, 1st to 2nd reflection, dual; Peak (level) or zero-cross comparator mode ToF resolution 100 [ps] Distance range 10 to 80 [mm], programmable as parameter

Compact size and low power (1W typ.)

Can be used with various chamber sizes

Pulser& Receiver

Pulser Type Single positive pulse, short circuit step pulser Pulse amplitude up to 360 [V] (no load), 256 steps Fall time <40 [ns]. PRF Typ. 750 [Hz], up to 1500 [Hz]. Receiver. Total gain range 100 [dB]. Adjustable gain range 0 to 80 [dB], 0.1dB step. Center frequency 1.0 [MHz]. Bandwidth (-3dB) 700 to 1400 [kHz].

Two channels for PT1000 RTD. Two channels for NDIR sensors. Support for external sensors or signals (4-20mA, 0-5V)

PT1000 channels (Ch1, Ch2)

Measurement principle Resistance ratio measurement (R-C discharge time measurements, on-board reference resistor) Connection 2- or 3-wire. Processing Programmable averaging, offset and gain coefficient. Resolution 0.001 [°C].

NDIR channels (Ch1, Ch2)

Supported type Dynament (Premier series) Interface RS232, 3.3V signaling. Power supply On-board switchable 3.3V regulator, up to 300mA (for both channels).

Analog input

Resolution 11-bit. Current mode. Sense resistance 270 [Ohm]. Range 0 to 22 [mA]. Voltage mode. Input resistance 100 [kOhm] (minimum). Range 0 to 6.0 [V]. Processing Offset correction, scaling coefficient, averaging

Open for developments (on request)

Transducers / UT probe

For different transducers (nominal frequency, size)


Open communication protocol (special commands, procedures)


Available with USB interface (virtual COM)


Support for easy firmware update. Support for other external sensors

Integration with other systems

Integration with other systems

OEM or standards

Configuration can be addopted to your own needs

E9324 - UltraGasQ Technology & Publications

The devices orignally was designed under Eurostar project: "E9324 - UltraGasQ Technology - Development of new technology and measuring instrument for express control of quality of natural gas
The main goal of the project has to develop an innovative UltraGasQ Technology for express control and real-time measurement of quality of natural gas and respective prototype of measuring instrument. The novel instrument will have distinctive competitive advantages relevant for a wide range of end-users (from private households to gas-grid operators and industry) – real-time & autonomous measurements of specific quality characteristics with sufficient accuracy at low capital and maintenance costs.

Real-time quality metering of propanated biomethane

Abstract:This paper presents a correlative method for the real-time measurement of quality characteristics of propanated biomethane for pipeline injection according to the European and Swedish regulations. The target quality properties (superior calorific value and Wobbe index) were predicted by the developed regression model based on the measurement of a selected set of physical properties of the gas samples. The measured physical properties are the thermal conductivity, the carbon dioxide concentration, the speed of sound, and the sound attenuation parameter measured as the ultrasonic signal dampening at 1 MHz. The empirical model of the sound attenuation parameter was developed for selected gases in order to predict a sufficient amount of data points for training the regression model. The developed regression model was tested experimentally and demonstrated good agreement with chromatographic analyses.

Keywords: Calorific value; Wobbe index; biomethane; propanated biomethane; ultrasonic measurement; speed of sound; ultrasound attenuation; correlative method; natural gas; time of flight; gas analysis.

International Journal of Oil, Gas and Coal Technology (Published: 2019)

Abstract:A new instrument for precise measurements of velocity of sound in gases was developed and tested. The instrument implements improved velocity of sound measuring technique based on time-of-flight measurement of ultrasonic pulses. The instrument was developed primarily for conducting measurements in natural gas, it can operate in wide ranges of natural gas compositions as well as other gas mixtures with velocity of sound parameter in range of 200 to 500 m/s. The instrument allows conducting measurement of velocity of sound propagation in various gas mixtures with average repeatability of equal to ±1 cm/s at normal conditions. The accuracy of measurement depends on calibration conditions and approach, and has good agreement with theoretically calculated values. The instrument has a modular design of control unit and flow-through measuring chamber. The set of distinctive features and adjustable measuring parameters of the instrument allows further improving of applicability for other gases and gas mixtures and various measurement conditions. The instrument showed good performance in the task of quantitative characterization of binary gas mixtures by velocity of sound parameter.

Keywords: ultrasonic measurement, velocity of sound, speed of sound, natural gas, time of flight, characterization of gas mixture, analysis of gas mixture.

Measurement Automation Monitoring 2016 | Vol. 62, No. 8 | 254--258