Geosense NexusGEO User manual
V1.1 May 2021
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MULTI-SENSOR
BLUETOOTH INTERFACE
NexusGEO
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ITEM PAGE
CONTENTS 2
1.0 INTRODUCTION 3
1.1 General description 3
1.2 Theory of operation 4
1.3 Software 4
1.4 Host system requirements 4
1.5 Electromagnetic compatibility 4
1.6 Theory of operation 5
2.0 CONFORMITY 6
3.0 MARKINGS 7
4.0 PACKAGING/HANDLING 7
4.1 Inspection & storage 8
5.0 GETTING STARTED 8
5.1 Batteries 8
5.2 Installing mobile app 8
5.3 Permissions 8
6.0 OPERATION 9
6.1 Connecting sensors 10
6.2 Using the app 11
6.2.1 Home and Bluetooth connection 11
6.2.2 Taking readings 13
6.2.3 Adding sensors 14
6.2.4 Selecting sensor 16
6.2.5 Site zero readings 17
6.2.6 Save readings 18
6.2.7 Edit sensor 19
6.2.8 Delete sensor 19
6.3 Data 20
6.3.1 FTP data 20
6.3.2 Email / save to file 21
6.3.3 Delete 21
6.3.4 Settings 21
6.3.5 Exported csv files 21
7.0 MAINTAINANCE 22
8.0 TROUBLESHOOTING 22
9.0 SPARE PARTS 22
10.0 SPECIFICATIONS 23
11.0 RETURN OF GOODS 24
12.0 LIMITED WARRANTY 25
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It is VITAL that personnel responsible for the use of
the NexusGEO READ and UNDERSTAND the manual,
prior to working with the equipment.
1.1 General Description
The NexusGEO is a portable multi-sensor battery-powered Bluetooth interface, designed to
be used with any Android device with Bluetooth and android OS 8 or later* for wireless
gathering and storage of sensor readings.
It is provided with a battery charger and four individually coloured leads to connect to
analogue sensors and a terminal block for digital sensors.
The NexusGEO is to be used with a mobile application (app) which has an easy to use
interface and manages data acquisition from the following single sensor outputs:
• Vibrating wire (VW)
• 4-20mA
• Volt
• mV/V
• Pt100
• NTC
• Geosense Digital RS485
*Please note that due to ever changing android device specifications, these specifications are subject to change
1.0 INTRODUCTION
This manual is intended for all users of the Geosense® NexusGEO readout unit and
provides a guide for its operation and maintenance.
Analogue connections can be made directly to the terminals, using the
fly leads with crocodile clips supplied with the unit or with the green
terminal block on the bottom of the unit for RS-485
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1.2 Theory of Operation
The NexusGEO is a Bluetooth interface between a range of sensors and an Android
device. The raw signal output from the sensor is transferred from the NexusGEO to the
Android device via the NexusGEO app and the values displayed on the Android device
where they can be converted into Engineering units, stored on the device and transferred
via FTP or email.
1.3 Software
The NexusGEO mobile application (app) allows the user to configure the device with a wide
range of sensor types and download the data. It is available as a free download on the
Google Play Store.
As part of continual improvement, updates to the software may occur and should be
downloaded to ensure the current version is being used. Please visit the Google Play Store
to check for the latest version.
1.4 Host System Requirements
• Android device with Android OS Version 8 or higher (Minimum SDK Version 19) and
Bluetooth
• In order to use FTP functionality, a FTP server will be required.
1.5 EMC – Electro Magnetic Compatibility
EMC is the electromagnetic interaction of electrical and electronic equipment with other
electrical and electronic equipment. All electronic devices have the potential to emit and be
affected by electromagnetic fields. With the reduction in size of electrical components and
the ever increasing amount of electrical & electronic devices such as mobile phones, two-
way radios, safety control systems, signalling, generators, welding equipment, power cables
etc in all environments, especially construction sites, there is a huge potential for devices to
interfere with each other.
The NexusGEO has been designed and tested for EMC under the relevant CE marking
directives to ensure compliance and reliable operation
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1.6 Philosophy of Operation
Calibration Factors
The NexusGEO is designed to work with a wide-range of sensors. Most sensors will require
calibration factors to convert from the raw reading into an engineering unit. All Geosense
sensors are dispatched with a calibration sheet with any factors that may be needed. Digital
sensors have the calibration information embedded in the sensor. The NexusGEO app will
allow you to enter this information when you add the sensor.
Wireless Connection and Data Reading
The NexusGEO uses wireless Bluetooth technology to communicate between the Android
device and the app. Once paired on the phone, connection can be established at the push
of a button, and begin taking readings moments later. Live readings are saved temporarily
in a buffer that clears when readings are stopped being taken.
Linear and Polynomial Calculations
Most sensors make use of calibration factors and raw readings to convert to engineering
units using either Linear or Polynomial calculations. The equations are detailed on the
calibration sheets.
Site Zero Readings
Sensors that convert to engineering units using Linear or Polynomial calculations can use a
site zero reading and apply this to the result to make it relative. If you choose to not apply a
site zero reading, the result will be absolute (site zero defaults to zero).
Saving Readings
As readings accumulate in the buffer, you can choose to save the readings into a database.
Sensor information, raw readings and engineering conversions are all saved for reference
later.
Using the Data
Saved data in the app database can then be saved to csv and sent via an FTP, Email or
saved to the local phone device for future use
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2.0 CONFORMITY
Geosense Ltd
Nova House
Rougham Industrial Estate
Rougham, Bury St Edmunds
Suffolk , IP30 9ND
United Kingdom
Tel: +44 (0)1359 270457
www.geosense.co.uk
EC Declaration of Conformity
We Geosense Ltd at above address declare that the equipment detailed below, complies
with the requirements of the following EU Directives:-
• Low Voltage Directive 2014/35/EU
• Electromagnetic Compatibility Directive 2014/30/EU
• Waste electrical and electronic equipment (WEEE) 2012/19/EU
• Restriction on the use of certain Hazardous Substances (RoHS2) 2011/65/EU
Equipment description: NexusGEO
Make/Brand: Geosense
Model Numbers: NxG
Compliance has been assessed with reference to the following harmonised standard:
EN 61326-1:2006 Electrical equipment for measurement, control and laboratory use.
EMC requirements. General requirements.
A technical file for this equipment is retained at the above address.
Marn Clegg
Director
Rougham, June 2019
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3.0 MARKINGS
A GeosenseTM NexusGEO is labelled with the following information:-
Manufacturers telephone number & website address
Product group: NexusGEO
Product type: NxG
Input supply: 12V DC
Serial number: NxG-XXXX
CE mark
WEEE mark
4.0 PACKAGING/HANDLING
The NexusGEO comes in a robust carry case and packed for transportation to site.
Packaging is suitably robust to allow normal handling by transportation companies.
Inappropriate handling techniques may cause damage to the packaging and the enclosed
equipment. The packaging should be carefully inspected upon delivery and any damage
MUST be reported to both the transportation company and Geosense.
The NexusGEO is a precision measuring instrument and its associated equipment should
always be handled with care during transportation, storage and use.
Once the shipment has been inspected, it is recommended that the GeosenseTM
NexusGEO components always remains in the carry case for storage or transportation.
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4.1 INSPECTION/STORAGE
It is important to check all the equipment in the shipment as soon as possible after taking
delivery and well before installation is to be carried out. Check that all the components
detailed on the documents are included in the shipment. Check that the equipment has not
been physically damaged.
The NexusGEO contains electronics and batteries and whilst they are designed for outside
use and mounted within a waterproof (IP66) enclosure the internal circuit board can be
affected by excessive moisture, dust and temperature. When not in use they should be
stored in a cool, dry location.
5.0 GETTING STARTED
This section of the manual is intended for all users of the NexusGEO and is intended to
provide guidance with respect to its use in obtaining data from a sensor.
5.1 BATTERIES
The NexusGEO has internal re-chargeable batteries which are not replaceable in the field.
If there is a problem with the batteries and change is required please return the unit to
Geosense.
5.2 INSTALLING MOBILE APP
In order to work with an Android device the NexusGEO Mobile app will need to be
downloaded from the Google Play store.
5.3 PERMISSIONS
To enable full functionality of the app, access permissions will be required. To enable
permissions on your phone go to Settings -> Apps -> NexusGEO -> Permissions ->
Storage and toggle this on.
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6.0 OPERATION
The unit compromises of:
1. Red, Black, Green and White terminal sockets for analogue connections
2. Bluetooth connection indicator
• Blue– Connected and taking readings
• Red– Disconnected
• Clear– No Bluetooth connection
3. Battery level indicator
• Green– Full battery level
• Amber– Half battery level
• Red– Low battery, charge immediately
4. On/Off power button
• On– Hold for 1 second to power unit on
• Off– Hold for 4 seconds to power off the device
5. RS485 digital connector
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6.1 CONNECTING SENSORS
The NexusGEO can be wired in the follow ways using the terminals or crocodile clips
provided to read analogue sensors. Ensure that each wire is fully secured before any
readings are taken.
It can also be wired to read a Geosense RS-485 digital sensor using the green connector
block on the bottom of the unit. Ensure that each wire is fully secured using the screw
terminals to establish connection.
NOTE: For other RS-485 sensors please contact Geosense®
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6.2 USING THE APPLICATION
6.2.1 HOME AND BLUETOOTH CONNECTION
Turn on the NexusGEO device by holding the power switch for 1 second. The device will
make a long audible beep and the battery light will display the current battery level for short
period of time before going clear. The power button can be pressed again to show the
battery level when required.
The battery indicator will periodically flash to indicate the device is switched on, and show
current battery levels.
The NexusGEO should be able to communicate with the app wirelessly via Bluetooth with a
range up to around 4 metres. On the android device turn on Bluetooth and pair with device
‘NexusGEO’. No pairing code is required.
Open the mobile APP on the android device and the following screen should be shown: -
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6.2.1 HOME AND BLUETOOTH CONNECTION CONT.
Menu Icons:
• Home
• Readings– Configure sensor and begin to take readings
• Data– Access any readings that have been saved and download them
• Settings
With the android device in range, tap the Bluetooth icon in the top right of the screen to
connect to the device. The icon will change to blue as shown below.
To disconnect from the device, press the Bluetooth icon again.
To turn off the NexusGEO, hold the power button down for 4 seconds. The device will make
short audible beep before all lights will turn off.
The Bluetooth indicator on the NexusGEO will remain clear until
readings being taken via the APP
The temperature and battery indicators in the APP will only update
when readings start being taken from the sensor
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6.2.2 TAKING READINGS
Pressing the Reading menu will show the following screen: -
Reading Menu Items:
• Add Sensor
• Select Sensor
• Edit Sensor
• Delete Sensor
Before readings are taken sensor information must be added, this includes sensor type and
calibration factors
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6.2.3 ADD SENSOR
Press ‘Add Sensor’ and the screen will change to:
The NexusGEO supports a wide range of sensors types, and each one has different
calibration factors that can be configured to convert to engineering units. Please refer to the
following table to the select the appropriate sensor type.
Sensor Type Calibration Factors Reading Units Engineering Units
4-20mA 3 Wire Sensor None mA None
4-20mA Crack Meter Linear (K)
Polynomial (A, B) mA Mm
4-20mA Piezometer Linear (K)
Polynomial (A, B) mA kPa, Bar, PSI, mH20
4-20mA Transducer Linear (K)
Polynomial (A, B) mA kPa, Bar, PSI, mH20
Inclinometer
(Analogue)
Linear (M, C)
Polynomial (A, B, C, D) mA Sin(X), Degrees, mm/M, Radians
Inclinometer (Digital) None Sin(X) Degrees, mm/M, Radians
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6.2.3 ADD SENSOR CONT.
Sensor Type Calibration Factors Reading Units Engineering Units
mV/V Displacement
Meter None mV/V None
mV/V Strain Gauge
Load Cell Linear (K) mV/V kN
NTC Temperature
Sensor None Ohms °C
PTC Temperature
Sensor None Ohms °C
Tiltbeam (Analogue)
Linear (M, C)
Polynomial (A, B, C,
D)
mA Sin(X), Degrees, mm/M, Radi-
ans
Tiltbeam (Digital) None as they are on
the chip Sin(X) Degrees, mm/M, Radians
Tiltmeter (Analogue)
Linear (M, C)
Polynomial (A, B, C,
D)
mA Sin(X), Degrees, mm/M, Radi-
ans
Tiltmeter (Digital) None as they are on
the chip Sin(X) Degrees, mm/M, Radians
Voltage Output Tiltme-
ter None VNone
Voltage Single None VNone
Vibrating Wire Crack
Meter
Linear (K)
Polynomial (A, B) Digit (B) mm
Vibrating Wire Dis-
placement Meter
Linear (K)
Polynomial (A, B) Digit (B) mm
Vibrating Wire Em-
bedment Strain
Gauge (50mm,
150mm, 250mm)
Batch Factor
Gauge Factor Digit (B) Microstrain
Vibrating Wire Hy-
draulic Load Cell
Linear (K)
Polynomial (A, B) Digit (B) kN
Vibrating Wire Liquid
Level Settlement
Linear (K)
Thermal (T)
Polynomial (A, B)
Digit (B) kPa, Bar, PSI, mH20
Vibrating Wire Load
Cell None Digit (B) None
Vibrating Wire Pie-
zometer
Linear (K)
Thermal (T)
Polynomial (A, B)
Digit (B) kPa, Bar, PSI, mH20
Vibrating Wire Pres-
sure Cell / NATM
Linear (K)
Thermal (T)
Polynomial (A, B)
Digit (B) kPa, Bar, PSI, mH20
Vibrating Wire Sister
Bar / Rebar
Linear (K)
Polynomial (A, B)
Strain (S)
Digit (B) kN, Microstrain
Vibrating Wire Soil
Extensometer
Linear (K)
Polynomial (A, B) Digit (B) mm
Vibrating Wire Spot
Weld Strain Gauge
Batch Factor
Gauge Factor Digit (B) Microstrain
Vibrating Wire Surface
Mount Strain Gauge
(89mm, 150mm)
Batch Factor
Gauge Factor Digit (B) Microstrain
Vibrating Wire Tem-
perature Transducer
Linear (K)
Polynomial (A, B) Digit (B) °C
Vibrating Wire Trans-
ducer
Linear (K)
Thermal (T)
Polynomial (A, B)
Digit (B) kPa, Bar, PSI, mH20
Vibrating Wire Weir
Monitor None Digit (B) None
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6.2.3 ADD SENSOR CONT.
With the appropriate sensor type selected, fill in the relevant factors and choose engineering
units (if required). Then press ‘Add Sensor’. A validation check will be made to make sure
sensor has a reference name and valid calibration factors.
When a sensor is added, the app will automatically go to the select sensor screen.
6.2.4 SELECT SENSOR
At the top of the select sensor screen there is a searchable select box displaying a list of
sensors currently configured on the aap. Select the sensor currently connected to the
NexusGEO and hold down the ‘Hold To Take Reading’ button for 1 second.
Note: Holding down the ‘Hold To Take Reading’ will give the user haptic feedback. This can
be turned off in the app settings.
The screen will change to show:
When adding sensors, some sensor types will add more than one
sensor into the app. This is because analogue connections can only
read from one sensor at a time, and so for instance with a biaxial
tiltmeter, a sensor will be added for each axis (A and B).
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6.2.4 SELECT SENSOR CONT.
This screen may differ slightly based on sensor type selected. The controls are: -
• Readings – live readings will update on screen approximately every second. Up to 3
readings can be shown on screen at the same time for the same sensor (Digital
tiltmeter shows A-Axis, B-Axis and Temperature).
• Raw Units / Engineering Units Selector – Will switch onscreen readings based on
information added during the sensor setup. Any calibration factors and engineering
units can be edited live whilst readings are being taken by pressing the edit sensor
button.
• Set Site Zero
• Save Readings
• Stop Taking Readings
As the app shows the live readings, they are stored in a temporary internal buffer, these can
be saved so that readings are not missed
6.2.5 SITE ZERO READINGS
Whilst taking a reading it is not possible to change the selected sensor,
or delete the selected sensor. To do this, stop taking readings.
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6.2.5 SITE ZERO READINGS CONT.
When converting raw readings into engineering units, a site zero reading can be set to make
the calculation relative, rather than absolute. This button enables the user to set, customise
and clear the site zero value. Any site zero value that is set, will be saved to the sensor and
automatically applied whenever the sensor is being read again (unless removed). The site
zero reading is being applied when the button changes colour to green:
6.2.6 SAVING READINGS
Readings can be stored from the temporary internal buffer using save button shown above
A default option for this selection can be saved in the settings screen,
which disables this screen from being shown when saving.
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6.2.7 EDIT SENSOR
After a sensor has been added, the edit sensor button
can be used to make changes to the sensor. Certain
information cannot be changed such as reference name
and serial number.
6.2.8 DELETE SENSOR
Select the sensor to be deleted and press the delete
button. The user will be asked to confirm this action.
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6.3 DATA
Any data that has been saved by the user when reading sensors is shown in this list (Most
recent data at the top). Controls are: -
• Select All / Deselect All
• FTP Upload
• Email / Save to File
• Delete
6.3.1 FTP DATA
Select which data sets are to be uploaded via FTP. Press the FTP button at the bottom left
of the screen. CSV files of the data are generated automatically with all readings and
information about the sensor.
An on-screen notification will alert the user when the upload has successfully completed.
CSV files are saved using the file name prefix ‘Export’ followed by a number. Be aware that
if a file already exists on the FTP server at this location, with this filename, it will be
overwritten.
FTP Settings need to be entered into the settings screen and the FTP
Connection Tested before taking advantage of this feature. Data
storage permission is also required to generate the temporary csv file
that will be uploaded.
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