Date Published: April 21, 2015
Application: Oil and Gas
Manufacturer: Next Industries
Measurements: 4-20mA, Flow
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4-Channel Compact Data Logger w/ GPRS modem

dataloggersRecently Next Industries supplied the datalogging solution for a wastewater treatment company looking to optimize its operation. In the natural gas industry, it’s a well-established technique to produce biogas by aerobic or anaerobic "digestion," starting from various biodegradable materials. The gas obtained this way consists of 60-70% methane, and can be used to fuel the digester’s boiler and electric generator engines.

The plant’s Utilities Director decided that the ideal way to incrase yields was to monitor and record the bio-digster’s gas flow. For example, immediately after feeding the digester there is usually a strong momentary increase in gas production, but there are also seasonal variations since cold temperatures inhibit production. Consequently, controlling the feed rate will improve the production process. The director also requires the capability to send alarms by SMS messaging.


The installed monitoring system is based on an industrial datalogger connected to two gas flow meter sensors. The key factors are the installation environment and the properties of the gas to be measured:

  1. The NEXT Industries miniOMNIAlog datalogger (151 mm x 136 mm x 90) is required here due to the need for an external installation. This compact instrument has an IP67-rated housing so it can be deployed outside control cabinets or enclosures. The logger’s complete conformal coating--a layer of transparent plastic film--acts as protection for the internal electronic boards against moisture and other contaminants. This ensures that the miniOmnialog can withstand industrial environments and maintain its high-precision measurement over the long-term.
  1. The gases are mainly composed of methane and carbon dioxide (CO2), but hydrogen sulfide (H2S) and wet vapor are also present. Since this can have corrosive effects, technicians have to use specific gas flow sensors: two BFM mass flow meters. The flow meters are connected to the miniOmnialog’s 4-20 mA inputs. One monitors the digester ouput and another measures the burned methane on the boiler. Each flow meter has two 4-20 mA ouputs: one for the gas flow and another for the temperature.

Standalone Operation and Alarm Transmission:

This datalogger has a powerful 32-bit CPU, with two GB (storing 4 million measurements) of internal non-volatile memory that provides for extended autonomous datalogging capability. Additionally the device’s electronic circuits are designed to reduce the power supply requirements to a minimum so that it can operate for several months (up to a year with 4 channels sending data every day) using the internal battery pack.

The alarm-generation capability the customer requires is performed by the miniOMNIAlog’s internal GPRS wireless modem. The data logger can be configured to send SMS messages and/or FTP and/or emails based on the measured data. Users can also activate a relay output in case of alarm.

While users mainly rely on the logger’s wireless connection transmit the measurement data, it’s also possible to download data using USB if desired.

Data Access from Smartphone and Tablet:

dataloggersUsers can remotely monitor the plant online via smartphone or tablet thanks to the OMNIAlog Cloud Web Portal. This optional cloud service enables users to monitor and control equipment and field devices quickly and efficiently.

Thanks to the cloud service users can drag and drop widgets to configure and build custom dashboards that display critical information visible even from a distance.


The miniOMNIAlog datalogger has both the necessary durability and small footprint for this deployment. With four channels and the internal modem it’s a cost-effective device. Additionally the OMNIAlog’s large memory is a useful feature for the plant’s need to document flow data for certification. Meanwhile the Cloud service enables remote monitoring and mimic generation. These features will help the director fine-tune his process and improve yields.

Categories Related To This Application

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Products Related To This Application

NI-400 miniOMNIALog 4 Channel Data Logger


NI-400 miniOMNIALog 4 Channel Data Logger

  • Measures: mV, mA, mV/V, NTC, Thermocouple
  • 2 GB internal memory and real time data
  • 0.05% F.S. Accuracy
  • Available GPRS version
  • 4 differential analog channels
  • Offers a virtual channel
  • Electromechanical relays for each measuring channel
  • 2 USB connections
  • IP67 rated