This relates to how many different output signals you have on the project and of course the quantities of each. It also relates to how often you require access to the data.
Standalone Dataloggers: These are generally used when data recording intervals are high but actual access to the data is fairly infrequent.
Remote Communication Dataloggers: These are generally used when access to the datalogger location is limited or not possible and data is needed on a continuous basis throughout a day. These will either contain a Radio link or a GPRS/GSM Modem.
The GeoLogger GL comprises of many different components to make a functioning logger system. There are many variations of this model which is reliant on the following variables:
- Number of sensors
- Output type of sensors
- Frequency required of downloading the data
- Method required for downloading the data
- What power requirements are available
- Recording interval
- Duration of project
- Location of sensors in relation to each other
It is best to consult a Geosense Technical Sales Engineer to determine the best solution for the job. Below are the most common components used in a GeoLogger GL and a brief description of its function and purpose:
CR800: This is the most frequently used datalogger and is suitable for most applications. It has 3 Differential and 6 Single ended inputs which is considered when plugging analogues sensors directly in the datalogger (i.e. no channel expansion required). This is particularly of use when dynamic readings are required and can achieve up to 100Hz. When considering the use of a channel expansion module (Flexi-Mux), Modem and a sensor interface, this would be the logger of choice. With the same spec, should there be more than 1 output of sensor for example RS485 and Vibrating Wire and a second sensor interface is required, a larger logger is required such as the CR1000. The logger has an RS232 port on the front so that you are able to hard wire to the logger to make any changes you may need or download the data directly.
CR1000: As above but with more channels to be able to deal with Channel Expansion (Flexi-Mux), Modem and 2 interfaces. This has 8 differential and 16 single ended analogue channels.
AVW200: This is the Vibrating Wire interface required for any logger with Vibrating Wire sensors terminating in it. Only one interface is required per Datalogger so you are able to Multiplex multiple VW signals before reaching the datalogger. If used independently, it can only cope with a maximum of 2 VW sensors.
GPRS Modem & SIM card: If remote access to the Datalogger is required via internet connection or dial-up, this component is compulsory. It requires two additional peripherals to function, a SIM card and Antenna. The SIM card must be 3G Data Enabled and have a fixed IP address. The antenna must be upright and pointing to the sky with line of sight if possible. Generally if you want to check to see if you will be able to communicate with the datalogger via the modem with the SIM card you have obtained, it is best to check with a mobile phone whether you are getting good signal or not. Remember, depending on the network the SIM card is assigned to, this will vary the signal strength. To check to see whether the Modem has signal with the SIM card plugged in, the red light on the modem should be flashing. If the red light is constantly on with no flashing, then the Modem is not getting signal. It is important to remember that the GPRS Modem is likely to be the most power hungry component in the GeoLogger GL. Something to keep in mind when deciding how many times you want to access the data.
RF416: This component is for radio communication between Datalogger and PC/laptop, or between outpost stations where you have remote sensors that were unable to wire back to the Central logger. Line of sight is preferable for this method of communication with a range of up to 500m being comfortable. If unsure, please contact a member of the Sales Team to discuss your requirements.
NL200: This component enables you to communicate with the Datalogger via an Ethernet cable. This is particularly useful if you want to be able to hook up to an internal network or simply a different method of communicating with the Datalogger via RS232.
Mains Trickle Charge: This is quoted if you have access to mains power which can accommodate voltages between 80 and 240V. This will always be supplied with a Battery back-up which once mains is plugged into, will automatically charge if the Voltage is low.
Solar Panel: If Mains power is not available and the Datalogger location is somewhere that will see sunlight, a Solar Panel is provided. Depending on the location, either a 5, 10 or 20W Solar Panel will be provided which can vary as well depending on how many times you would be looking to access the data via a modem (if included). This will be supplied with a Pole Mounting kit and instructions on how to assemble. Generally a larger battery is also supplied (around 75aH), when a solar panel is used.