Hontzsch flowtherm NT User manual

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Operating Instructions
flowtherm NT
Software status from 2.01
Multifunctional handheld unit with data logger for measuring flow rate,
flow velocity, temperature, pressure and other variables

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Overview and brief introduction of controls and connections
For settings and other
functions see Section 5
Please ensure that the correct sensor (FA, VA or TA) is selected (see under 5.3.20.1)!
Thermal sensors TA, TADi
Always connect just one sensor at a time!
Vane wheel sensors FA(R), FT,
FA(R)Di or vortex sensors VA, VAT, VADi
or temperature sensors Pt100
2 analog outputs 0-10 V
analog input 4-20 mA
analog input 0-10 V
Connector socket cap
Close any connections not in use!
Measured value display
Input channel 1: name/unit
value
Input channel 2: name/unit
value
Input channel 3: name/unit
value
Function keys Designation
Function keys
, , with variable
functions depending on
operation menu
USB connection type 'B'
for connecting to PC or
adapter plug
Switch off
and reset
Switch on
Input channel
and status info
Battery compartment
for 4 batteries / recharge-
able batteries Mignon (AA)
Arrow keys (measured value dis-
play)
,: shift between
1, 2 and 3 values
, : scroll the 3 values
with display of 1 and 2
values
ok key (measured value display)
: switching the display light on
or off
Holding magnet
for fixing the unit to
metal surfaces

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Contents
1Safety Instructions.....................................................................................................................4
1.1 Specific information...........................................................................................................4
1.2 Handling batteries and accumulators ...................................................................................5
1.3 Precautions for hazardous areas..........................................................................................5
2Scope of Delivery.......................................................................................................................6
2.1 Description, type plate.......................................................................................................6
3Technical Specifications ..............................................................................................................8
3.1 Operating conditions..........................................................................................................8
3.2 Housing and connection .....................................................................................................8
3.3 Electrical data...................................................................................................................8
3.4 Measurement uncertainty...................................................................................................9
4Initial Operation / Startup ...........................................................................................................9
4.1 Connector sockets.............................................................................................................9
4.2 Wiring diagram for the 8-pin connector plug .......................................................................10
4.3 Wiring diagrams for the 12-pin connector plug.................................................................... 11
5Operation ............................................................................................................................... 12
5.1 Key functions..................................................................................................................12
5.2 Setup menu after switch on: ............................................................................................ 14
5.3 Parameter settings ..........................................................................................................16
5.3.1 FA - Basic settings .............................................................................................16
5.3.2 FA - Measurement settings..................................................................................17
5.3.3 FA - Density correction .......................................................................................18
5.3.4 FA –Operating conditions ................................................................................... 19
5.3.5 FA –Standard conditions ....................................................................................19
5.3.6 FA - Pairs of values ............................................................................................ 19
5.3.7 VA - Basic settings ............................................................................................. 20
5.3.8 VA - Measurement settings .................................................................................20
5.3.9 VA –Operating conditions ...................................................................................21
5.3.10 VA –Standard conditions .................................................................................... 21
5.3.11 VA - Pairs of values ............................................................................................22
5.3.12 TA - Basic settings .............................................................................................22
5.3.13 TA - Measurement settings..................................................................................22
5.3.14 TA –Standard conditions .................................................................................... 23
5.3.15 TA - Pairs of values ............................................................................................24
5.3.16 Pt100 - Unit ......................................................................................................24
5.3.17 Analog input......................................................................................................24
5.3.18 Output..............................................................................................................25
5.3.19 Counter ............................................................................................................25
5.3.20 Display ............................................................................................................. 25
5.3.21 Long-term measurement ....................................................................................27
5.3.22 Device .............................................................................................................. 29
5.3.23 Factory settings .................................................................................................29
5.3.24 Data logger ....................................................................................................... 29
5.3.25 Device status..................................................................................................... 30
5.3.26 Device profiles ...................................................................................................31
5.3.27 Key F3 - LM-Start .............................................................................................. 31
5.3.28 Key 4 Switch off / OFF (reset) .............................................................................31
6Troubleshooting.......................................................................................................................32
7Replacement Parts ................................................................................................................... 33
8Instruction Manual Category 3G flowtherm NT ............................................................................. 33
8.1 Equipment .....................................................................................................................33
8.2 Safety Instructions ..........................................................................................................33
8.3 Technical Data ................................................................................................................34
8.4 Installation..................................................................................................................... 34
8.5 Maintenance ...................................................................................................................34
9Declaration of conformity..........................................................................................................35

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1Safety Instructions
Danger to life, risk of injury and damage to material or property.
Read the Operating Instructions carefully before initial operation.
Observe general safety precautions as well as those included in various sections of these Operating
Instructions.
Hazard risks:
-non-observance of the Operating and Safety Instructions
-modifications to the device by the customer
-handling the device outside the specified operating conditions
-handling the sensors outside the specified operating conditions
-use of unsuitable power supplies and peripheral devices
-improper use of the device
Prevention of voltage hazards:
-use only the dedicated adapter plug for the mains supply
-make sure that the PC is correctly connected to the mains (earthed safety socket, earthing) when
using a USB connection
-when connecting analog outputs or inputs to peripheral devices make sure that these are correctly
connected to the mains (earthed safety socket, earthing)
Danger when installing the sensors in pressurized pipelines:
-sensors for use in pressurized pipelines are to be inserted or retracted only in depressurized con-
ditions; non-observance may result in serious injuries to personnel
-when installing or removing under pressure, the appropriate protective equipment must be used, e.g.
ball valve and probe guide pieces with chain guard or spindle probe guide pieces
Danger when using in explosive atmospheres:
-the unit and its sensors may be used in areas specified for category 3G (zone 2 gas) equipment only
-if sensors with category 1/2 G, 1/2 D or 2 G, 2 D or 3 D markings are connected to the device they
may be used in category 3G areas only! (See also Instruction Manual Category 3G and
Declaration of Conformity in Sections 8 and 9)
1.1 Specific information
-pay special attention to the mains voltage when using voltage converters
-observe the maximum power rating when connecting sensors powered by more than 12 V
-when operating out of doors make sure that the battery compartment cover and sensor plug are
screwed on tightly, the connector sockets not in use are firmly capped, and the USB connection cover
is tightly sealed, otherwise the IP65 protection cannot be guaranteed

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1.2 Handling batteries and accumulators
-All batteries/accumulators must be replaced at the same time. Do not replace single cells! All replace-
ments must be identical (cell type / nominal capacity / make) and fitted the right way round. Possible
reverse polarity of single cells is to be avoided (electrolyte formation)
-Recharge batteries with a suitable charger away from the unit
-Remove batteries when they are dead or if the device is not being used for any length of time to avoid
leakage
-Batteries contain hazardous substances and must never be disposed of in household waste
-Never recharge normal batteries
1.3 Precautions for hazardous areas
-It is prohibited to use rechargeable batteries in hazardous areas
-Do not connect or disconnect plugs in hazardous atmospheres. This also applies to connected sensors
which must be mechanically screwed in place
-Use of the USB port in hazardous areas is not allowed without the protective USB cover
-Use of the USB port as a power supply is prohibited
-It is forbidden to change batteries in the hazardous environment
-Prior to measuring always check that the battery compartment is closed correctly to ensure that the
batteries are securely fixed. The compartment cover must be screwed on tightly before use
-If severe fluctuations in temperature are to be expected, the device should be left to adapt
to the ambient temperature for at least one hour before use to avoid problems with condensation.
In particular, the battery contacts should be checked for condensate or corrosion as well as leakage
-Devices in which the batteries have leaked must on no account be used in hazardous atmospheres, but
must be returned to the manufacturer for repair
-Mechanical shocks are to be avoided
-Damaged instruments should be checked before use. If in doubt, return to the manufacturer for inspec-
tion

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2Scope of Delivery
-handheld flowtherm NT
-Operating Instructions and Data Sheet flowtherm NT
-FA, VA or TA sensor(s) as ordered
-relevant Data Sheet for above
-other sensors such as Pt100, if ordered
-accessories for sensors, e.g. extension rod for FA sensor, if ordered - CD-ROM with PC software HLOG
II and USB cable (optional)
-adapter plug and USB cable (optional)
-various connection and extension cables, connectors (optional)
-carrying case (optional)
Please check that everything listed in the Delivery Note / Technical Data Sheet is included in the delivery.
2.1 Description, type plate
The flowtherm NT is a multifunctional handheld unit with data logger for measuring flow velocity, volume
flow/flow rate, standard flow rate, mass flow rate, temperature, pressure and other variables, insofar as
they are measurable / deducible with connectable sensors:
-vane wheel FA, FAR, FT, FADi, FARDi
-vortex VA, VAT, VADi
-thermal TA10, TADi
-temperature Pt100
-2-wire 4-20 mA 12 V supply
-3- or 4-wire 4-20 mA output and 12 V supply
-3- or 4-wire 0-10 V output and 12 V supply

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The following type plate is found on the back of the unit:
Description of type plate specifications:
1: Description
see Section 2.1
2: Unit and serial no.
3: Marking for Ex-application category 3G
see Safety Instructions Section 1
see Instruction Manual Category 3G Section 8
see Declaration of Conformity Section 9
4: Inputs
see Description Section 2.1
see Connector sockets Section 4.1
see Wiring diagrams Section 4.2 and 4.3
5: Outputs
see Electrical data Section 3.3
see Connector sockets Section 4.1
see Wiring diagrams Section 4.3
6: USB connection
see Electrical data Section 3.3
see Connector sockets Section 4.1
7: Power supply
see Safety Instructions Section 1
see Electrical data Section 3.3
8: Operating conditions
see Safety Instructions Section 1
see Operating conditions Section 3.1
1
2
3
4
5
6
7
8

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3Technical Specifications
3.1 Operating conditions
Ambient temperature
of connection housing in service : -20 ... +50 °C
Type of protection : IP65
3.2 Housing and connection
Type of protection : IP65 with battery compartment cover and sensor plug screwed on
tightly, connector sockets not in use firmly capped, and USB connection
cover tightly sealed
Material : electrically conductive ABS plastic
External measurements, weight : W/H/L = 96/42/197 mm, approx. 520 g
Connections : 5-pin connector plug for thermal sensors
: 8-pin connector plug for vane wheel, vortex or temperature sensors
12-pin connector plug for analog outputs or inputs
USB for data logger readout, configuration and external power supply
via PC or mains adapter
3.3 Electrical data
Power supply : via 4 alkaline manganese (LR6) Mignon (AA) 1.5V batteries
(maximum permissble nominal capacity 4000 mAh per cell)
running time (Duracell Plus) approx. 24 hours
(using FA sensor without display light)
or via 4 NiMH rechargeable Mignon (AA) 1.2V batteries
running time (Ansmann Digital 2850 mAh) approx. 26 hours
(using FA sensor without display light)
Open the battery compartment with a screw driver. Always change all 4 batteries at the same time,
checking for correct polarity. Only ever recharge batteries away from the unit using a suitable charger.
Always ensure that all 4 rechargeable batteries are fully charged before inserting. To close the compart-
ment press it firmly in the seal (in the direction of the connector sockets) and screw down tightly.
Mains supply : via USB connection with PC or adapter plug
Supply current : via USB connection not less than 300 mA
The mains supply is not electrically isolated from the outputs.
The "-" connection of the analog outputs and the earth of the USB connection have the same potential, i.e.
for EMC reasons a peripheral device should have potential-free inputs for evaluation of the analog outputs
when connecting to a PC.

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Analog outputs (2 x) : 0 ... 10 V with internal resistance of 1000 Ohm; measured, initial and
final values adjustable as appropriate
Analog input 4-20 mA : for connection of sensor in 2-wire system with 12 V;
allocation of unit, initial value and final value adjustable
Analog input 0-10 V : for connection of sensors with voltage output; input resistance 5 MOhm;
12 V power supply for sensors, max. 100 mA; allocation of unit, initial
value and final value adjustable
3.4 Measurement uncertainty
Input FA : +/- 1 Hz
Input VA : +/- 1 Hz
Input TA : +/- 1 (0.7 % of measured value + 0.02 % FS)
Temperature display : +/- 1 Kelvin
Analog input 0-10 V : +/- 1 (0.3 % of measured value + 0.02 % FS)
Analog input 4-20 mA : +/- 1 (0.3 % of measured value + 0.02 % FS)
Input Pt100 : +/- 0.2 Kelvin
Analog output 1+2, 0-10 V : +/- 1 (0.2 % of measured value + 0.02 % FS)
All values apply for a set damping rate of 30 seconds during measurement. In addition, the measurement
uncertainty of the utilised sensors must be taken into consideration.
4Initial Operation / Startup
For installation and operation of the system, especially in category 3G, the national regulations
currently in force, the recognised standards of good practice and these Operating Instructions
apply.
4.1 Connector sockets
5-pin connector socket:
for thermal sensors TA10 and TADi measuring tubes
8-pin connector socket:
for vane wheel sensors FA, FAR, FT and FADi measuring tubes
for vortex sensors VA, VAT and VADi measuring tubes
for temperature sensors Pt100

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2
8
6 7
4
1
5
3
Always connect just one sensor at a time!
Always make sure that the connector sockets not in use are firmly capped, the sensor plug is
screwed on tightly and the USB connection cover is tightly sealed, otherwise the IP65 protection
cannot be guaranteed
4.2 Wiring diagram for the 8-pin connector plug
Electrical connection must be carried out according to the relevant wiring diagram.
Incorrect connection can cause serious damage to the electronics.
Wiring diagram with view of solder contacts:
Pin assignment
Pin 1: v/FA+FAR signal 1 For v/VA signal F
Pin 2: ground G
Pin 3: Pt100
Pin 4: Pt100
Pin 5: Pt100
Pin 6: Pt100
Pin 7: v/FAR signal 2 F
Pin 8: V+
Housing: shield
12-pin connector socket:
for analog outputs 2 x 0-10 V
for analog input 4-20 mA
for analog input 0-10 V
USB connector socket type B
data logger readout, hardware configuration
for external power supply via PC or adapter plug

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4.3 Wiring diagrams for the 12-pin connector plug
Electrical connection must be carried out according to the relevant wiring diagram.
Incorrect connection can cause serious damage to the electronics.
Wiring diagrams with view of solder contacts:
4.3.1 Analog outputs 0-10 V
C = analog output port 1
D = analog output port 2
E = signal - (0 V)
plug shell = shielding
4.3.2 Analog input 4-20 mA
(2-wire system current
for 12V supply)
A = power supply + (12V)
F= power supply –
plug shell = shielding
4.3.3 Analog input 4-20 mA
(3 or 4-wire system current
for 12V supply)
A = power supply + (12V)
B = power supply –(0V)
F= signal +
H = signal - (0V)
plug shell = shielding
4.3.4 Analog input 0-10 V
(3 or 4-wire system voltage
for 12V)
A = power supply + (12V)
B = power supply –(0V)
G = signal +
H = signal –(0V)
plug shell = shielding

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5Operation
5.1 Key functions
Switch on: with the key (also symbol)
hold down until text appears in the display.
Switch off: with the key (also symbol)
press briefly and wait until the display goes off.
Reset! Should the unit no longer react to key operation, switch off can be enforced by holding down
the off key for more than 10 seconds.
Control keys: , and are keys with variable function, identified in the bottom
row of the display depending on user level.
Arrow keys: In measured value display / view after switch on:
during measured value display the arrow keys have the following function:
and : shift the display. Definition whether the values from 1, 2 or 3
input channels are displayed simultaneously. Depending on selection, the
character size of the display value changes.
and : is the display so set that only measured values from 1 or 2
input channels are displayed simultaneously, then these keys can be used for scroll-
ing through the input channels.
In the menus and input boxes:
, , and are control keys for navigating within the various menus
and menu levels.
ok key: In the measured value display / view after switch on:
is a control key for switching the display light on or off.
In the menus and input boxes:
is a control key to select and save.

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Examples for key functions in the menus:
Menu selection list:
With up or down in the list; the selected element
is highlighted.
With a menu level higher (backwards).
With a menu level lower (forwards) = select.
With select = a menu level lower (forwards).
With return to measured value display.
With switch off.
Parameter value selection window:
With new selection element; the selected element
flashes (here "mn").
With select and save and return to selection list.
With return to measured value display without saving.
With return to selection list without saving.
With switch off.
Parameter value digit (numeric/text) setting:
With change digit; the selected and editable
digit flashes (here "1").
With 1 digit to the left or right respectively.
With select and save and return to selection list.
With return to measured value display without saving.
With return to selection list without saving.
With switch off.

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5.2 Setup menu after switch on:
Menu
Settings
Sensor
FA input
Basic settings 5.3.1
Type 5.3.1.1
Range 5.3.1.2
Material 5.3.1.3
Directional sensing 5.3.1.4
Measurement settings 5.3.2
Medium 5.3.2.1
Section 5.3.2.2
Profile factor 5.3.2.3
Damping 5.3.2.4
Density correction 5.3.3
Operating conditions 5.3.4
Service temperature 5.3.4.1
Working pressure 5.3.4.2
Standard conditions 5.3.5
Standard temperature 5.3.5.1
Standard pressure 5.3.5.2
Standard density 5.3.5.3
Pairs of values 5.3.6
VA input
Basic settings 5.3.7
Type 5.3.7.1
Measurement settings 5.3.8
Section 5.3.8.1
Profile factor 5.3.8.2
Damping 5.3.8.3
Operating conditions 5.3.9
Service temperature 5.3.9.1
Working pressure 5.3.9.2
Standard conditions 5.3.10
Standard temperature 5.3.10.1
Standard pressure 5.3.10.2
Standard density 5.3.10.3
Pairs of values 5.3.11
TA input
Basic settings 5.3.12
Type 5.3.12.1
Measurement settings 5.3.13
Section 5.3.13.1
Profile factor 5.3.13.2
Pressure 5.3.13.3
Damping 5.3.13.4
Standard conditions 5.3.14
Standard temperature 5.3.14.1
Standard pressure 5.3.14.2
Standard density 5.3.14.3
Pairs of values 5.3.15
Pt100 input
Unit 5.3.16
Analog input 5.3.17

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Menü
Settings
Output 5.3.18
Port 5.3.18.1
Source 5.3.18.2
Counter 5.3.19
Reset 5.3.19.1
Decimals 5.3.19.2
Display 5.3.20
Sensor 5.3.20.1
Rows 5.3.20.2
Row 1 5.3.20.3
Row 2 5.3.20.4
Row 3 5.3.20.5
Long-term measurement 5.3.21
Mode 5.3.21.1
Device 5.3.22
Factory settings 5.3.23
Data logger 5.3.24
Switching on / off 5.3.24.1
View 5.3.24.2
Settings 5.3.24.3
Delete 5.3.24.4
Status 5.3.25
Profiles 5.3.26
Switch off 5.3.28
LM-Start
5.3.27
Logger
Switching on / off 5.3.24.1
View 5.3.24.2
Settings 5.3.24.3
Delete 5.3.24.4
Off/ Reset
5.3.28

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5.3 Parameter settings
Settings for vane wheel sensors FA:
5.3.1 FA - Basic settings
Menu -> Settings -> Sensor -> FA input -> Basic settings
The connected vane wheel sensor determines the parameter type, measuring range, material and direc-
tional sensing to be set.
5.3.1.1 Type
Setting the vane wheel type:
This can be determined from the serial no. on the sensor.
Selection: mc = micro - for use in for instance:
cylinder probes with OD 14, 16, 18 mm
measuring tubes with ID 9.7 mm
mn = mini for use in for instance:
cylinder probes with OD 25 mm
measuring tubes with ID 18.2 mm
md = midi for use in for instance:
cylinder probes with OD 30 mm
pairs of values = special calibration characteristic specifically matched to the
measuring task based on up to 30 supporting points. Input or
changing the points, see under 5.3.6
Distinctive feature of sensors with vane wheel types md3 and ms (measuring tube):
These sensors are always supplied with a special calibration characteristic. Therefore, always select pairs
of values. For input or change see (5.3.6) pairs of values.
5.3.1.2 Range
Setting the vane wheel measuring range:
This can be determined from the serial no. on the sensor.
Selection: 20 = measuring range up to 20 m/s
40 = measuring range up to 40 m/s
80 = measuring range up to 80 m/s
120 = measuring range up to 120 m/s
Exceeding the measuring range can cause permanent damage to the vane wheel!
5.3.1.3 Material
Setting the vane wheel sensor material:
This can be determined from the serial no. on the sensor.
Selection: steel = E
aluminium = A
titanium = T
5.3.1.4 Directional sensing
Setting the directional sensing function: such sensors are identified by an "R" in the serial number.
Selection: Y= directional sensing yes, measured value display with prefix
N= directional sensing no, measured value display without prefix

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5.3.2 FA - Measurement settings
Menu -> Settings -> Sensor -> FA Input -> Measurement settings
The task to be carried out determines the parameter, medium, section and profile factor to be set.
5.3.2.1 Medium
Setting the medium:
Selecting pairs of values in the basic settings (5.3.1.1) has no impact on the measurement.
Selection: G= Gases, the characteristic for air/gases is applied
F= Liquids (Fluids), the characteristic for water/liquids is applied
Use only "GF" sensors (see technical documents) for measuring in liquids; otherwise the sensor can
be permanently damaged!
5.3.2.2 Section
Setting the measuring section for measuring in pipelines for flow rate display:
Selection: Circular = for pipes with circular section
di/mm: enter the ID in mm
Rectangular = for pipes with rectangular section
a/mm: enter the inner surface a in mm
b/mm: enter of the inner surface b in mm
5.3.2.3 Profile factor
The profile factor PF specifies the ratio of mean flow velocity in the measuring section and the flow velocity
measured from the sensor. Requirements are: centric sensor positioning, non-rotational inlet flow and
adequately dimensioned input/output sections. (See also Documents U117 and U205)
Following profile factors are to be set for vane wheel cylinder probes (ZS..) subject to pipe diameter:
Pipe ID
in mm
PF for ZS16 (mc)
PF for ZS18 (mc)
PF for ZS25 (mn) and
ZS30 (md)
40
0.914
0.898
50
0.933
0.916
0.735
60
0.950
0.932
0.760
70
0.964
0.948
0.784
80
0.976
0.962
0.807
90
0.987
0.975
0.829
100
0.994
0.986
0.849
120
1.004
1.004
0.882
170
1.008
1.021
0.935
180
1.008
1.021
0.945
220
1.008
1.021
0.955
...
1.008
1.021
0.955
For measurements in larger free jet as well as larger ducts or measuring tubes PF = 1.000 results in the
local/punctual velocity.
With TABLE a profile factor subject to the vane wheel type (5.3.1.1) and diameter of the measuring
surface (5.3.2.2) is recommended. This value can be verified or also amended before saving. If rectang-
ular is selected, the surface is converted to circular for the proposed value and this value is approximate.
If the sensor is a ZS18 (mc), the value must be amended according to the table above.
PF = 1.000 must always be set for FADi... measuring tubes calibrated with pairs of values!

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5.3.2.4 Damping
The damping rate set here affects the measured value display, if FA is selected as sensor in the display
settings (5.3.20.1). Damping also affects the analog output if FA is selected as the source (5.3.18).
Damping/s: enter the damping time of 01 to 99 seconds
Example 10 seconds: after every second the arithmetical average of the last 10 seconds is displayed.
5.3.3 FA - Density correction
Menu -> Settings -> Sensor -> FA Input -> Density correction
Liquids:
Liquids are virtually density resistant. No density correction needed.
Gases and vapours:
The density of gases and vapours can be strongly modified against pressure and temperature. Such severe
modifications have a minor impact on the measured value of a vane wheel sensor. This impact manifests it-
self in a determinable correction value, which is added to or subtracted from the measured value. The per-
centaged impact of this correction value is however negligible with average to high velocity flow. With low and
very low values, consideration of the density correction becomes more expediant.
To determine this correction value the measuring range initial value (starting value) of a vane wheel is
examined. The specified starting value in the vane wheel sensor documents arises from a medium density of
1.204 kg/m³ (calibration conditions). The only slightly deviating actual starting value, even with considerably
different working density of the medium (in the actual application) ensues in good approximation of the
following:
actual starting value = specified starting value x root of (density during calibration / working density of the
medium).
The correction value is now the difference between real and specified starting value. The characteristic of the
sensor is displaced by this value.
If the operating density of the medium is greater than the calibration density of 1.204 kg/m³, then the deter-
mined correction value must be deducted from the measured value. If it is less than the calibration density of
1.204 kg/m³, then the determined correction value must be added to the measured value.
The working medium density is needed to calculate the correction value.
Example:
A ZS25GE-mn40/100/p10 sensor with a specified starting value of 0.5 m/s is used in air at 1.013 bar and
100 °C, that is, with a working medium density of 0.946 kg/m³.
Entered in formula:
actual starting value = 0.5 m/s x root of (1.204 kg/m³ / 0.946 kg/m³) = 0.5 m/s x 1.128
= 0.564 m/s
correction value = 0.564 m/s –0.5 m/s
= 0.064 m/s
With a displayed value of 15.00 m/s (without correction) and with density correction on, the correction value of
0.064 m/s would be allowed for and a corrected value of 15.06 m/s would be displayed.
Setting:
Selection: N= density correction no
Y= density correction yes then enter the density of the sample gas:
W-density/kg/m3: enter the working medium density in kg/m³

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If the working medium density is not known, it can be determined with the formula:
W-density = P / (R * T)
where P = absolute pressure in Pa, R = specified gas constant in J/(kg*K), T = temperature in K.
Here the specified gas constants of some gases:
sample gas
specific gas constant
in J/(kg*K)
sample gas
specific gas constant
in J/(kg*K)
dry air
287
hydrogen H2
4124
steam H2O
462
methane CH4
518
argon Ar
208
nitrogen N2
297
carbon dioxide CO2
189
oxygen O2
260
carbon monoxide CO
297
propane C3H8
189
helium He
2077
sulphur dioxide SO2
130
5.3.4 FA –Operating conditions
Menu -> Settings -> Sensor -> FA input -> Operating conditoins
When choosing the relevant units (see 5.3.20.6) service temperature and working pressure are needed for
calculation purposes. The operating conditions can be entered in this menu or determined with connected
sensor.
5.3.4.1 Service temperature
Measured or entered unit in °C
5.3.4.2 Working pressure
Measured or entered unit in hPa
5.3.5 FA –Standard conditions
Menu -> Settings -> Sensor -> FA input -> Standard conditions
Standard conditions for Höntzsch are +21 °C (70 °F) and 1014 hPa (14.7 psia). Any standard can be set
via the standard temperature and standard pressure parameters.
5.3.5.1 Standard temperature
Input value in °C
5.3.5.2 Standard pressure
Input value in hPa
5.3.5.3 Standard density
Input value in kg/m³ depending on set standard conditions for calculating the mass flow rate.
5.3.6 FA - Pairs of values
Menu -> Settings -> Sensor -> FA Input -> Pairs of values
If pairs of values is selected (see 5.3.1.1), then the values stored here for determining the measured
value are applied as a calibration curve.
Selection: Configuration = enter the quantity of pairs of values (minimum 2, maximum 30)
for processing and display
Pairs of values = display and amend pairs of values.
A pair of values always consists of a velocity value in m/s
and a frequency value in Hz.
The condition being: the pairs of values must be ever
increasing, i.e. the next velocity and frequency value must always
be greater than the previous one.

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Example for quantity = 03
01:000.50m/s, 00010Hz
02:010.00m/s, 00350Hz
03:040.00m/s, 01770Hz
If the frequency measured value is greater than in the last pair of values, then the velocity value is
calculated. However, this means that the measurement uncertainty increases as this value is then outside
the calibrated range. The measuring range in the serial no. and technical data sheet must not be
exceeded, as this may cause permanent damage to the vane wheel! (For further information refer to
5.3.1).
Settings for vortex sensors VA:
5.3.7 VA - Basic settings
Menu -> Settings -> Sensor -> VA Input -> Basic settings
The connected vortex sensor determines the parameter type.
5.3.7.1 Type
Setting the type:
Refer to the relevant technical documents for selection options.
Selection: KKZ = the calibration number (KKZ) is individually determined for each
sensor and modifies the basic characteristics.
KKZ: enter as an 8-digit figure, in which each digit has a
0..9..A..F range (hexadecimal = 16 possible variables).
The actual KKZ can be found in the technical data sheet, calibration
certificate or directly on the sensor
pairs of values = special calibration characteristic specifically matched to the
measuring task based on up to 30 supporting points. Entering or
amending the points, see under 5.3.11.
The actual pairs of values are documented in the technical
documents.
5.3.8 VA - Measurement settings
Menu -> Settings -> Sensor -> VA Input -> Measurement settings
The measuring task to be carried out determines the parameter, section and profile factor to be set.
5.3.8.1 Section
Setting the measuring section for measuring in pipelines for flow rate display:
Selection: Circular = for pipes with circular section
di/mm: enter the ID in mm
Rectangular = for pipes with rectangular section
a/mm: enter the inner surface a in mm
b/mm: enter the inner surface b in mm
5.3.8.2 Profile factor
The profile factor PF specifies the ratio of mean flow velocity in the measuring section and the flow velocity
measured from the sensor. Requirements are: centric sensor positioning, non-rotational inlet flow and
adequately dimensioned input/output sections. (See also Documents U155 and U206).
Following profile factors are to be set for vortex sensors VA40 subject to the pipe diameter: