New process laser spectrometer from Yokogawa

The Yokogawa Electric Corporation has announced the release of the TDLS8000 tunable diode laser spectrometer. This new product can quickly make in-situ measurements of gas concentrations in combustion and heating processes that are employed in the oil, petrochemical, electric power, iron and steel, and other industries, allowing quick and efficient combustion control.

Yokogawa’s laser gas analyser instruments make use of tunable diode laser spectroscopy (TDLS) to measure the gas concentration. To make the measurement, a receiving unit detects how much energy is absorbed as a laser beam, tuned to the correct absorption frequency of the gas to be monitored, is transmitted through the duct carrying the mixed gas stream. With this technique, there is no need for a sampling device: the analyser can be installed directly on a gas duct and make measurements quickly, in real time. Yokogawa’s analysers use a unique spectrum area method whereby the gas concentration is calculated based on the area in an absorption-distribution chart, and thus can stably measure the concentration of a specific gas in the presence of other gases or dust and under conditions where the temperature and/or pressure is fluctuating.

Improving combustion efficiencies
Companies are always looking for ways to optimise processes by saving energy, reducing CO2 emissions, and improving safety. An important way to do this is by optimising the air-fuel ratio in the combustion process. To accomplish this, sensors are needed that can continuously monitor the concentration of Oxygen and both Carbon Monoxide and Methane from the fuel in the radiant section of fired heaters.

The Yokogawa TDLS200 laser gas analyser, originally released in 2008, is an instrument capable of quickly performing in-situ measurements of the concentration of the near-infrared absorbing (paramagnetic) gases such as O2, CO, CO2, and NH3. Since the launch of this innovative product seven years ago, its high accuracy and precision have earned it a good reputation in the marketplace, and the TDLS200 has become one of the best-selling instruments of its type in the global market (admittedly based on market surveys conducted by Yokogawa).

The TDLS8000 is being introduced as the successor to the TDLS200 to satisfy the need for improved operability and to allow for greater adaptability in difficult applications.

Features of the new TDLS8000
1. Highly reliable measurement
The TDLS8000’s laser module includes a newly developed reference cell board that improves the reliability of absorption peak detection, which is an important step in the spectral area method. In addition, the receiving unit employs a new auto gain function that can automatically optimise detection sensitivity depending on the measurement object. By increasing the signal-to-noise ratio (S/N ratio), this improves the reliability of measurements taken in coal combustion and other processes where there is high particulate loading. Designed to meet the requirements for SIL2 certification (certification pending) defined by the International Electrotechnical Commission (IEC), the TDLS8000 will play a key support role in ensuring the safe operation of plants.

2. Improved operability and maintenance efficiency
The TDLS8000 comes with a large 7.5-inch LCD touch screen that can display a greater variety of data. The touch screen replaces the push button interface used with preceding models, making the setting of parameters easier and more intuitive. The light source module containing the laser diode is fully sealed and damage resistant. To facilitate troubleshooting and reduce downtime, this module is able to store up to 50 days’ worth of raw data that can be accessed anywhere in the world by, for example, a Yokogawa response centre.

3. Compact size
The new design of the TDLS8000 unit is just three-quarters the size and weight of the preceding model, allowing it to be installed in a greater variety of locations.

Yokogawa TDLS8000 Tunable Diode Laser Spectrometer

Yokogawa TDLS8000 Tunable Diode Laser Spectrometer

As the successor to the TDLS200 laser gas analyser, the TDLS8000 offers improved reliability and operability. With this new product, Yokogawa aims to capture a greater share of the gas analyser market by offering a solution that will make it possible to improve plant efficiency and safety. Major target markets include industries such as oil and gas, petrochemicals, chemicals, electric power, iron and steel, and ceramics.

Applications include measurement of O2 concentration in fired heaters for improved safety and lifecycle management; measurement of the Carbon Monoxide concentration during the combustion process; measurement of the amount of moisture in hydrocarbons and corrosive gases; and measurement of ammonia concentration for leak detection during the DeNox process.

Yokogawa plan to certify the TDLS8000 to the IECEx, ATEX (Europe), FM (US), cFM (Canada), and TIIS (Japan) explosion-proof standards. It will be suitable for installation in hazardous areas that require the use of an explosion-proof enclosure.