This document outlines specifications for a groundwater data logger and telemetry system. Key requirements include: - The system must include a pressure sensor, data logger, telemetry unit, and data retrieval software. - The pressure sensor must measure groundwater levels accurately between 0-50m or 0-70m and withstand high pressures. - The data logger stores at least 200,000 data points, operates for over 2 years on batteries, and supports wireless data transmission. - The telemetry unit transmits data via GPRS/GSM once per day for 1 year on batteries and sends alerts for failures. - The software downloads and displays data on a laptop in common formats like Excel.

1. 10.005(B) DWLR, PRESSURE TYPE (GW)
Including Telemetry System
Approval Date: October 2010 Version: 1
Sl.
no
Feature Tender Specifications
1.0 PRESSURE SENSOR
Sensor Type Vented Gauge Pressure Sensor
Measuring Range The measuring range may be specified by the
Implementing Agency depending upon the local
Ground Water level condition. For different
Ground Water applications, the overall
accuracy is specified as follows:
0-50m (water column) : 5 cm or better
0-70m (water column) : 7 cm or better
Overall Accuracy 0.1% Full Scale or better (Including sensor
and Data logger) The pressure readings
should be fully temperature and pressure
compensated over the entire operating range.
Temperature Coefficient <0.01% Full scale/degree centigrade on water
level reading.
Reproducibility 0.05% full scale.
Long Term Stability 0.1% Full Scale and should ensure long term
stability without any field calibration
requirements.
Burst pressure >3 times Full scale.
Overload pressure 2 times full scale. Overload pressure is the
maximum pressure the sensor should sustain
without effect on calibration upon return to rated
measuring range.
Equipment Specification: DWLR, PRESSURE TYPE(GW) WITH TELEMETRY Version 2
10.005(B)-1/6

2. Over voltage protection
on supply & sensor wires
Over voltage protection should be provided on
power supply lines.
2.0 DATA LOGGER
Resolution of
measurement
12-bit AD converter or better (Appropriate
resolution of ADC to achieve the desired
accuracy)
Measuring interval &
measuring modes
Should be programmed to store data from 1
minute one reading to 24 hours one reading in
linear sampling mode, should have selectable
(i) linear, (ii) logarithmic and (iii) event
measuring modes .
Settling up Time < 30 minutes after submersion.
Recording capacity Non-Volatile flash data storage of more than
200000 data points (at least).
Memory type Non-Volatile Memory
Power supply Should be equipped with lithium or alkaline
battery pack in standard size, like AA, C or D size, ideally
readily available in India, with an option of an external battery
pack that can provide operational life more than 2 years, again
with user replaceable standard lithium or alkaline batteries ideally
readily available in India.
Preferably, the batteries are kept inside a
separate enclosure, above the maximum water
level. Alternatively, batteries may be kept inside
the data logger enclosure. However, wherever
the batteries are kept, they shall be easily
replaceable, in the State workshop by the local
technician, ideally using batteries readily available in India.
Communication Interface The communication hardware (IR/Bluetooth/USB
2.0 or better with RS 232 serial port as optional)
between DWLR and Palmtop/Laptop PC shall be
suited for the specified cable lengths for above
specified communication.
In case of online monitoring is required, it
should support GSM/GPRS capability.
Operating temp Up to 50°C
Equipment Specification: DWLR, PRESSURE TYPE(GW) WITH TELEMETRY Version 2
10.005(B)-2/6

3. Built in clock Accurate to ± 2 minutes per year
Displayed time resolution 1 second
Over-voltage protection Should include lightening, over voltage and surge
protection
3.0 Enclosure for Pressure
sensor and data logger
Data logger should be concealed into a single
tubular enclosure which is waterproof and
corrosion proof.
Dimensions Outer diameter : < 50 mm, length <500 mm.
Material Titanium or Stainless Steel (AISI 316). All DWLR materials
and combinations thereof shall be corrosion proof.
Operating temperature Up to 50 0
C
Humidity 100 %
Cable
The cable shall have following features.
 Strength members for good longitudinal
stability of cable.
 Incorporated vent tube for barometric air
pressure compensation of the vented gauge
pressure sensors.
 A moisture blocking system based on a
hydrophobic filter and desiccator, to prevent
condensation of water in the vent tube and in
the sensor. The desiccant shall be
replaceable.
 The desiccant capacity should be adequate
for atleast 6 months of unattended operations
under the worst environmental conditions. For
each instrument, two desiccant replacement
should be part of the delivery.
 Cable screen to be connected to the data
logger ground terminal to minimize electrical
interference.
 A cable suspension bracket allowing the
DWLR to be adjusted to the required depth, in
a stable and reproducible manner.
 The cable and contacts should be fixed or
quick connect.
Equipment Specification: DWLR, PRESSURE TYPE(GW) WITH TELEMETRY Version 2
10.005(B)-3/6

4.  Corrosion and moisture free as the equipment
has to work under water condition.
 Cable should have good flexibility.
 Should be of Polyurethane Jacket or better
 The electrical wires shall have sufficient
conductivity to allow for extension of the cable
to up to 150m without degrading accuracy,
stability and data communication.
Vent Tube PTFE or equivalent
4.0 Telemetry System GPRS/edge based data transmission system with
at least one month power backup (see
supplementary Specification)
5.0 Data Retrieval System
(DRS)
Pocket PC/ Laptop Latest Palmtop/Laptop PC available with colour
display with Windows Mobile 5/XP/Vista.
Capable of displaying, downloading and storing
data for at least 10 DWLRs for 6 months x 6
hours frequency data. Should have at least RS232
serial port/ two USB 2.0 or better ports to connect a DWLR or a
PC, Wi-Fi and IrDA/Bluetooth wireless/ optional RS232 port
technology for data communications. Palmtop should have
minimum 192 MB hard disk, minimum 256 MB RAM. Laptop
should have minimum 40GB hard disk, minimum 1 GB RAM.
DWLR Shall include the delivery of cables,
connectors and adaptors for downloading and
uploading the data from and to the DWLR and
Palmtop/laptop.
System should be capable of programming,
controlling and monitoring of DWLRS.
Entry /Display/Readability The unit should have a colour LCD screen/display shall
be easily readable in field conditions.
Software
Windows based software for instrument
control and display of downloaded data in
tabular and graphical presentation form.
The DWLR should include a software for
down loading data from DWLR and exporting
the same to desktop PC in MS Office
formats*
.
Equipment Specification: DWLR, PRESSURE TYPE(GW) WITH TELEMETRY Version 2
10.005(B)-4/6

5. Power Supply All batteries associated with the DRS, i.e. the
batteries for normal operation and the backup
batteries, shall be easily replaceable by the local
operator ideally using lithium or alkaline batteries
readily available in India, and/or rechargeable.
Laptop should have integral rechargeable battery
pack.
5.0 Carry case A dedicated carry case should be provided.
*The MS Office format viz. MS Excel, MS Access etc. should be defined in the bidding document.
Equipment Specification: DWLR, PRESSURE TYPE(GW) WITH TELEMETRY Version 2
10.005(B)-5/6

6. Specifications for
Ground water Data Transmission System
The transmission system should be tightly integrated with the DWLR along with compact
remote/field mounted systems consisting of data logger, modem and antenna in one single metal cast
housing (Die Cast Aluminium);
1. The system should be watertight (IP67) and impact resistant;
2. The system should allow easy access into the well for control measurements without
removing complete system;
3. System must be power-supplied by standard lithium batteries for operation time of
minimum one year by one set of batteries (one transmission per day, 4 measurements per
day) and must be placed in a separate water resistant (IP68) cylindrical container hanging in
the pipe below the main unit or on the surface.
4. The system must have integrated energy management system using free programmable
time slots for measurement and transmission to minimize power consumption;
5. The connectors should be water-tight (IP67).
6. An alarm notification must be sent by the system via SMS to four mobile phone numbers
through suitable means of communication in case of station component failure. This
includes battery performance and life expectancy.
7. A standard USB communication interface should be available for set up and configuration
and must be easily accessible.
8. All measurement and set up options, data download and programming of data logger shall
also be done by online session similar to all functions at site by direct connection to a PC or
PDA without any difference;
9. Option for Blue Tooth/IR/Wi-Fi interface should be available
10. Data download / retrieval from remote PC Via GSM/GPRS network compatible to 850,
900, 1800 and 1900MHz (Quad Band) under software control. Output of this
software should be in standard ASCII/CSV/XML format.
11. The software should be provided to allow download of data from the data logger on to a
Laptop in the field.
Equipment Specification: DWLR, PRESSURE TYPE(GW) WITH TELEMETRY Version 2
10.005(B)-6/6

7. Specifications for
Ground water Data Transmission System
The transmission system should be tightly integrated with the DWLR along with compact
remote/field mounted systems consisting of data logger, modem and antenna in one single metal cast
housing (Die Cast Aluminium);
1. The system should be watertight (IP67) and impact resistant;
2. The system should allow easy access into the well for control measurements without
removing complete system;
3. System must be power-supplied by standard lithium batteries for operation time of
minimum one year by one set of batteries (one transmission per day, 4 measurements per
day) and must be placed in a separate water resistant (IP68) cylindrical container hanging in
the pipe below the main unit or on the surface.
4. The system must have integrated energy management system using free programmable
time slots for measurement and transmission to minimize power consumption;
5. The connectors should be water-tight (IP67).
6. An alarm notification must be sent by the system via SMS to four mobile phone numbers
through suitable means of communication in case of station component failure. This
includes battery performance and life expectancy.
7. A standard USB communication interface should be available for set up and configuration
and must be easily accessible.
8. All measurement and set up options, data download and programming of data logger shall
also be done by online session similar to all functions at site by direct connection to a PC or
PDA without any difference;
9. Option for Blue Tooth/IR/Wi-Fi interface should be available
10. Data download / retrieval from remote PC Via GSM/GPRS network compatible to 850,
900, 1800 and 1900MHz (Quad Band) under software control. Output of this
software should be in standard ASCII/CSV/XML format.
11. The software should be provided to allow download of data from the data logger on to a
Laptop in the field.
Equipment Specification: DWLR, PRESSURE TYPE(GW) WITH TELEMETRY Version 2
10.005(B)-6/6