Login 
For years, KELLER’s GSM-2 has provided a simple way of remotely tracking pressure measurements, fill and water levels, and monitoring limit values. Now, this proven data logger with remote data transmission unit has been upgraded and given a new name: ARC-1, the Autonomous Remote Data Collector.
Upgrading with the times
In the interests of compatibility, the ARC-1 incorporates the same functions as the GSM-2 but also includes some new features:
- It now communicates via the 3G mobile network, or 4G if required. The new radio modules also allow the device to be located via the mobile network.
- The mini SIM card has given way to a micro SIM card. The data logger can also be supplied with an e-SIM upon request.
- The system status information, including battery status and signal strength, has been supplemented by a moisture sensor.
- A real-time clock (RTC) has been integrated into the data logger which is more accurate and continues running autonomously when the battery is changed.
Existing GSM-2 data loggers can also be upgraded easily to ARC-1 data loggers if the existing 2G network at the measuring point is no longer available.
Preserving proven features
The new generation has not changed in appearance. At just 48 mm in diameter, the cylindrical design of the ARC-1 can simply be placed into the top of a twoinch- wide sounding tube standard in the groundwater measuring industry. It can be installed in a matter of seconds.
The housing is designed to withstand condensation and temporary flooding. The sealed antenna is covered by a lockable protective cap made of robust plastic. This protects the data logger against theft and damage by people or wild animals when level measurements are being taken in the open countryside.
Complete with energy-efficient electronics and a premium-quality lithium battery (3,9 V/32 Ah), the logger can transmit the results of 24 measurements every day by email, SMS or FTP for up to ten years. Its fastest measurement rate is one measurement per minute.
With two input voltages (0…5 V), two digital inputs, one bus interface (RS485) to operate up to five level sensors and an optional SDI12 interface for water analysis devices, the ARC-1 data logger is a universal data collection module for wide area measurement networks.
Free PC software
The flexible, easy-to-use, open-source “DataManager” software covers the key functions of a monitoring, collection, control, and organisational unit for the ARC-1. The DataManager collects the measurement data, assigns it, puts it in charts, reports any limits that have been exceeded, and stores it in an open-source mySQL database. Third parties can access the measurement data by means of various export and Internet functions for integration into their own data collection systems. The DataManager software also enables users to fully parameterise and monitor each individual ARC-1 data logger.
Kolibri Cloud
The Kolibri Cloud from KELLER offers simple and convenient access to your measurement data with your own personal login and SSL encryption. You can enjoy readily available data without the need to set up and maintain a database, FTP or mail server. The measurements can be displayed as graphs in no time at all and the export function allows you to download your data as Excel or CSV files. Measuring points are effortlessly and efficiently monitored with the integrated alarm system. For instance, a warning can be triggered via email if there is an increase in water level or a battery is running low.
The Kolibri Cloud API allows customer-specific software to call up measurements in a standardised JSON format via HTTPS.
The ARC-1 is available as a tube or box. All of the designs can be ordered as 3G, 4G, or LoRa versions. An intrinsically safe version of the box can also be supplied upon request.
