Hydreka 801 User manual

801 Operation Manual Page 1
HYDREKA
Model 801
Electromagnetic Flow Meter
Operation Manual

801 Operation Manual Page 2
CONTENTS
SECTION DESCRIPTION PAGE
1. INTRODUCTION ..................................................................................................................3
2. EQUIPMENT .................................................................................................................. 3
2.1. Standard 801 System............................................................................................................. 3
2.2. Wading Accessories.............................................................................................................. 3
2.3. Options .................................................................................................................. 3
3. DESCRIPTION ..................................................................................................................4
4. SYSTEM OPERATION .................................................................................................................. 6
4.1. Setting up ..................................................................................................................6
4.2. Switch on ..................................................................................................................6
4.3. Running the unit ...............................................................................................................7
4.4. Setting Units, Averaging Mode and Averaging Period ........................................................ 9
4.4.1. Changing Averaging Period.................................................................................... 10
4.5. OPTIONS menu [Logging, Beeper, Backlight, Direct EM Comms].................................... 11
4.6. LOGGING menu .............................................................................................................. 12
4.6.1. Change Date/Time .................................................................................................. 13
4.6.2. Viewing stored data ................................................................................................ 14
4.6.3. Extracting data ........................................................................................................ 15
4.7 Analogue output [factory fit option] ..................................................................................... 16
5. POWER SUPPLY ..................................................................................................................17
5.1. Changing batteries................................................................................................................. 17
5.2. Battery Life .................................................................................................................. 17
5.3. External power [factory fit option] ....................................................................................... 17
6. CALIBRATION .................................................................................................................. 18
7. CARE AND MAINTENANCE .......................................................................................................... 20

801 Operation Manual Page 3
1. INTRODUCTION
This manual covers the operation of the Model 801 Electromagnetic Flow Meter.
2. EQUIPMENT
2.1. Standard 801 System
The standard 801 system has a choice of sensors and comprises the following, and can be used with either 19 or
20mm diameter wading rods which customers may already have for use with impeller current meters:
0801013 Single axis, cylindrical sensor c/w 2m cable and connector
or
0801004 Single axis, flat sensor c/w 2m cable and connector
0801006 Wading Rod adaptor [only supplied for the flat sensor 0801004]
0801007 Allen Key for wading rod adaptor
0801005 Control and Display Unit
0801008 Carrying case
0801811 Operating manual
2.2. Wading Accessories
The following accessories are available for wading operations:
0801003 Set of 3 off 0.5 metre wading rods, graduated in centimetres, base and direction knob
0801010 Canvas shoulder bag for wading accessories
2.3. Options
0300012 Data cable to computer
0801011 Larger carrying case to take complete system with wading rods [instead of standard case
and canvas shoulder bag]
Analogue output option

801 Operation Manual Page 4
3. DESCRIPTION
The 801 electromagnetic flow meter uses the Faraday principle to measure the flow of water past the sensor. Two
different types of sensor are available for the 801: the cylindrical sensor and flat sensor.
The cylindrical sensor has its electrodes on the side and the volume of water that is being sensed is a spherical
volume around the sensor to a diameter of about 120mm. Because of this relatively large sensing volume, the
cylindrical sensor should not be used in situations where the water boundary [bottom, sides or surface] is closer
than 40mm to the sensor.
The flat sensor has the sensing electrodes on one surface of the sensor and these should normally be facing
uppermost. The volume of water whose flow is being sensed is a cylinder between the electrodes and extending to
approximately 10mm above the sensor. This sensor is therefore also suited to shallow applications. Because of the
small sensing volume, if the water is turbulent, the real time readings of the flat sensor will fluctuate more than
those of the cylindrical sensor.
The sensor should be aligned into the flow and the calibration is determined for +ve flow [flow on to the sensor at
the electrode end] with the sensor upstream of the wading rod.
The sensor will detect negative flow and the same calibration is used, although there will normally be some
interference caused by the turbulence from the wading rods. The unit is set to measure speeds up to 5 M/sec in
both directions.
The system is calibrated as a combination of sensor with electronics in the Control Display Unit, and the serial
number of both the probe and the CDU are displayed on the display on start up.
The system will operate in any conducting fluid, and the conductivity does not effect calibration. At very low
conductivities the signal will, however, become noisier. A simple check is to check the noise in still water.
The CDU has its own internal batteries, and bulkhead connectors for the data interface to PC and the sensor.
There is also a waterproof pressure equalising valve, to compensate for changes in temperature and atmospheric
pressure that would otherwise cause the display membrane to distort. The connectors have waterproof pro-caps for
when not in use. The CDU is designed for operation in rain conditions and for temporary immersion in water to
0.3m for 10 seconds, provided all connectors or pro-caps are fitted.
FLOW
FLOW
Sensing Volume of
Cylindrical Sensor
Sensing Volume of
Flat Sensor

801 Operation Manual Page 5
The EM system measures the flow twice every second, and calculates the real time
flow every second as the average of the half second readings. The REAL TIME
display is updated every second. The average speeds are computed as the average of
the one second real time values over the averaging period which has been set
[maximum period of 600 seconds]. If an average period is terminated early, then
the calculation is based on the time since the average was started.
The 2Hz data from the EM system has been digitally filtered from raw 96Hz data.
The filter is a Digital FIR filter with a fixed time delay and no frequency
dependent phase shift. The filter –3dB cut off is 0.27Hz, and the delay time is
3.5 seconds.
The STANDARD DEVIATION [SD] is calculated from real time samples taken during the
averaging period and gives an indication of the quality of the measurements. A
high standard deviation indicates either a high variability in the flow, or the
probe has not been held steady during the measurement.
There are 3 types of Averaging Modes:
Fixed average:
The unit performs one average over the period set. At the end of the averaging period the unit
stops and displays the average and SD. It will commence another averaging period when
requested by pressing START.
Free running:
This is fixed average with automatic restart of averaging period at the end of each period. The
average and SD from the previous period are displayed and held during the subsequent period,
until updated.
Moving average:
The average and SD are calculated over the averaging period set, and is updated every second.
When STOP is selected, the display is frozen at the last average.
If the measurement period is terminated prematurely [by pressing the STOP key], the average values and
standard deviation will be calculated over the time since the start of the current averaging period.
The data [speed, SD, averaging period] is available for direct interfacing to a PC in real time [see Section
4.6.3. for interfacing information]:
In fixed average a data string of average data is outputted at the end of averaging period.
In moving average the last saved average is outputted when the user presses the STOP key.
In free running mode the data is outputted at the end of each fixed average period and also when the user
presses the STOP key.
The CDU can log up to 999 averages for subsequent display and/or transfer to a PC.
The analogue output is +/-5volts for the speed range +/-5 M/sec, and the analogue signal is based on the latest
average figure shown on the CDU. The analogue output connector also enables external DC to be applied.

801 Operation Manual Page 6
4. SYSTEM OPERATION
4.1. Setting up
To prepare the system for use:
i] Clean the probe electrodes to remove any grease or dirt.
ii] Insert batteries [8 off 1.5v C type cells], if external power not being used. It is recommended that alkaline type
cells are used for maximum life.
iii] Connect cables for particular combination of hardware being used.
iv] If using with probe fixed to wading rods then assemble probe into adaptor [clamping using the small grub
screw] and fix to rods, base and direction knob assembly.
v] If mounting the probe by other means, it should be noted that the mounting may affect the flow characteristics
and thus introduce an error into the measurement. Users can of course adjust results by carrying out their own
calibration.
Once the system has been connected up, it is ready for use. For testing purposes, all of the CDU operations can be
carried out without the sensor in water, but the real time data will be meaningless.
4.2. Switch on
ON Switch unit On using ON button. This is acknowledged by a beep from
the unit. This key is also used to switch the unit Off at any point during
operation. Switching the unit On causes the following display to appear:
CONTINUE Places the unit in Run Mode. See Section 4.3.
OPTIONS SET-UP This key selects the OPTIONS menu, which allows the user to set up
various hardware configurations [Logging On/Off, Beeper On/Off and
Backlight On/Off]. This menu also allows access to the USER
CALIBRATION menu, and to the LOGGING MENU. For further
information refer to Section 4.5.
801SINGLEAXISEMFLOWMETER
VALEPORT MODEL 801 VER 2 . 00
EM Ser No 17668 UNIT Se r No 17115
<<<OPT IONS SETUP CONT INUE>>>

801 Operation Manual Page 7
4.3. Running the unit
Pressing CONTINUE at the title screen, or pressing EXIT at any of the OPTION SET-UP screens [see Section
3.6] reveals one of the three possible displays shown below, depending on what mode the unit was in when last
used [note that until START is pressed, no flow data is displayed].
DISPLAY 1: FIXED AVERAGE
FIXED AVERAGE 801 HH:MM:SS
STOP>>>
TTT SSS SECS
SETUP>>>
REAL AVERAGE
+ X . XXX + X . XXX M/ SEC SD=X . XXX START>>>
LOW B
A
TT
DISPLAY 2: MOVING AVERAGE
MOVING AVERAGE 801 HH:MM:SS
STOP>>>
SSS SSS SECS
SETUP>>>
REAL AVERAGE
+ X . XXX + X . XXX M/ SEC SD=X . XXX START>>>
DISPLAY 3: FREE RUNNING
FREE RUNN I NG 8 0 1 HH : MM : SS
STOP>>>
TTT SSS SECS
SETUP>>>
REAL AVERAGE
+ X . XXX + X . XXX M/ SEC SD=X . XXX START>>>
An explanation of the different averaging modes can be found in the Description, Section 3.
SETUP Press this key to alter current sampling regime. See Section 4.4.
START After an initialisation period of about 10 seconds, during which the
following display will appear, the unit will begin sampling in the mode
which has been set. The real time data will be displayed at the bottom of
the screen, updated every second. In Free Running and Fixed Average
modes, the count down within the average period is displayed. If the unit
is in logging mode, the current record number will be displayed at the top
right hand side of the screen. If the data interface lead is connected, the
end of average values will also be sent to the PC.

801 Operation Manual Page 8
INITIALISING EM
PLEASE WA I T
STOP Press to cease sampling. This will force an early end to an averaging
period at the next second.
LOW BATT When there is approximately 4 hours of battery life remaining [with
backlight], this message will be displayed at the bottom right hand corner
of the screen [see DISPLAY 1 for an example]. The message will remain
until batteries are replaced. See Section 5. for more information on power
consumption and battery life.

801 Operation Manual Page 9
4.4. Setting Units, Averaging Mode and Averaging Period
Selecting SET-UP in the Run Menu reveals the following display.
RUN MENU SETUP
<<<M/ SEC FT / SEC OPT IONS>>>
<<<F I XED MOVING FREE ACCEPT>>>
<<<AVERAGE PER I OD SSS SECS
M/SEC FT/SEC Toggles between measuring the Speed in metres and feet per second.
FIXED MOVING FREE Toggles the averaging mode between the three states. Refer to Section 3
for further details.
AVERAGING PERIOD The Averaging Period which has been set is displayed. If it is required to
change this, then press the key to move to the “Change Sampling” page.
Refer to Section 4.4.1.
OPTIONS Press this key to return to the OPTIONS menu [Section 4.5.]
ACCEPT When the sampling regime is correctly set up, press this key to return to
the RUN menu [Section 4.3.].

801 Operation Manual Page 10
4.4.1. Changing Averaging Period
Selecting AVERAGING PERIOD in the RUN SET UP screen reveals the following display:
INCR DECR Toggles between increasing and decreasing the number of seconds when
the relevant key is pressed.
100'S Changes the number of 100's of seconds in the averaging period.
10'S Changes the number of 10's of seconds in the averaging period.
1's Changes the number of 1's of seconds in the averaging period.
EXIT Returns to the RUN MENU SETUP screen [Section 4.4].
Note that "000" seconds cannot be set, and the maximum is 600 seconds.
CHANGE SAMP L I NG
<<<100 ' S
<<<10 ' S INCR DECR>>>
SSS SECONDS
<<<1 ' S EX I T>>>