entegris InVue NT6520 User manual

INVUE™ INTEGRATED
FLOW CONTROLLERS,
MODELS NT6510, NT6520
User guide
P/N 01-1032525 (Rev. A 09/15) CRITICAL MATERIALS HANDLING

ENTEGRIS, INC. USER GUIDE 1
INVUE INTEGRATED FLOW CONTROLLERS, MODELS NT6510, NT6520
Table of Contents
Introduction ....................... 2
Identifying Nonstandard
Product Configurations ...... 2
Principle of Operation ......... 2
Factory Configured ............. 3
Continuous versus
Batch Control ................. 3
Calibration Reference
Conditions ..................... 3
General Considerations ......... 4
Power Supply Requirements ... 4
Storage Temperature Range ... 4
Operating Ambient
Temperature Range .......... 4
Operating Process
Temperature Range .......... 4
Line Pressure .................... 4
Pressure Drop.................... 4
Dimensions ...................... 5
Installation ........................ 9
Provided Equipment ........... 9
Mounting Requirements ...... 10
Mechanical Installation ...... 11
Power Supply Requirements .. 12
Electrical Connections ....... 14
Wiring Diagram ................ 16
Optional Connections ......... 17
Setpoint Signal Setup ......... 18
Calibration Graphs ............ 19
Unit Operation .................. 20
Operating Environment ...... 20
Performance ................... 21
Operational Reliability ........ 22
Status and Alarming .......... 22
LED Status Codes ............. 23
Diagnostic Guide ................. 24
Maintenance .................... 27
Normal Operation ............. 27
Re-zero Function .............. 27
Reference ........................... 28
Physical Specifications ....... 28
Electrical Specifications ..... 28
Performance Specifications ... 28
Ordering Information .......... 29
Certifications ................... 32
CE Compliance ................ 32
Repair and Warranty Service ... 32
Technical Support .............. 32
For More Information ......... 32
Terms and Conditions ......... 32
Product Warranties ............ 32

2 USER GUIDE ENTEGRIS, INC.
INVUE INTEGRATED FLOW CONTROLLERS, MODELS NT6510, NT6520
Introduction
This manual is for use with a standard
InVue ™ Integrated Flow Controller,
Models NT6510 and NT6520. These
instruments have been designed for
use in high-purity fluid applications
within industries that need tightly
controlled chemical processes such
as the semiconductor, biomedical
and solar cell industries. The wetted
parts are constructed with Modified
PTFE, PTFE, PFA or other similar
high-purity inert materials.
WARNING! Attempting to install or
operate standard InVue Integrated
Flow Controllers without reviewing
the instructions contained in this
manual could result in personal
injury or equipment damage.
Identifying Nonstandard
Product Configurations
This User Guide applies to product
manufactured as the standard
InVue Integrated Flow Controller.
Entegris also manufactures non-
standard product to meet the needs
of specific applications. Nonstandard
product may have different materials
of construction, accuracy specifi-
cations, performance and other
specifications that differentiate the
nonstandard product from the stan-
dard offering.
NOTE: Nonstandard InVue Inte-
grated Flow Controllers may be
identified by the model number
found on the product label.
Specifications for nonstandard
InVue Integrated Flow Controllers
are available by contacting Entegris.
Nonstandard InVue Integrated Flow
Controllers, Model NT6510, are
identified with an “N” followed by
a number code.
For example, in part number
6510-T2-F03-B06-A-P7-U3-N02, the
“N02” designates the product as a
nonstandard product manufactured
to certain specifications designated
under the “N02” code.
Nonstandard InVue Integrated
Flow Controllers, Model NT6520,
are identified with an “R” followed
by a number code.
For example, in part number
6520-T6-F03-B06-A-P7-U3-R02, the
“R02” designates the product as a
nonstandard product manufactured
to certain specifications designated
under the “R02” code.
Contact Entegris for assistance with
nonstandard product applications.
Principle of Operation
The user provides a setpoint signal
that corresponds to the desired
amount of flow. The standard InVue
Integrated Flow Controller compares
the setpoint to the actual flow signal
from the flow module. If the actual
flow is greater than the setpoint, the
unit closes the valve. If the actual
flow is less than the setpoint, the
unit opens the valve. The flow con-
troller does this in a precise manner
until the actual flow signal is equal
to the setpoint.
!

ENTEGRIS, INC. USER GUIDE 3
INVUE INTEGRATED FLOW CONTROLLERS, MODELS NT6510, NT6520
Factory Configured
The standard InVue Integrated Flow
Controller is pre-configured from the
factory for the flow range specified
by the user. The specified flow range
is found on the label of the unit. The
unit control algorithm uses pressure
and flow measurements to ensure
proper operation within specification.
Continuous Versus
Batch Control
The standard InVue Integrated
Flow Controller may be ordered
as a continuous type controller or
a batch type controller.
The continuous controller type is
for applications requiring continuous
flow rate control, where the integral
valve module is never required to
fully close. Typically, another valve
is used in conjunction with the flow
controller to stop the liquid flow.
The batch controller type is for appli-
cations requiring flow rate control
where the integral valve module will
fully close between batch dispense
cycles. If total volume needs to be
controlled, an additional separate
totalizer device must be employed.
Calibration Reference
Conditions
Unless otherwise noted, the speci-
fications listed for the InVue Inte-
grated Flow Controller are referenced
under the following operating
conditions:
Parameter Reference Condition
Process fluid Deionized water
Process
temperature
23°C ±3°C (73°F ±5°F)
Ambient
temperature
23°C ±3°C (73°F ±5°F)
Process pressure 207 kPa (30 psig)
for operating range
option 10–100% of
full scale flow
("T" code flow range)
276 kPa (40 psig)
for operating range
option 5–100% of
full scale flow
("Y" code flow range)
Supply voltage 24 VDC ±10%
Operation Re-zeroed
NT Integrated Flow Controller System Diagram
Powe
r
S
etpoint
Re
-zero
Sensor
measurement
Valve
control
Fluid
flow
Fluid
flow
Pressure signal
Flow signal
Alarm
NT Integrated Flow Controller
control interface
Flow/valve module

4 USER GUIDE ENTEGRIS, INC.
INVUE INTEGRATED FLOW CONTROLLERS, MODELS NT6510, NT6520
General Considerations
The following requirements and
specifications are briefly provided
here. Before installing and operating
the InVue Integrated Flow Controller,
see the Installation and Unit Opera-
tion sections of this user guide for
more detailed information.
NOTE: The flow controller has been
factory sealed. Do not attempt to
remove the cover of the unit. Any
attempt at removal of the unit
cover will void the warranty.
Power Supply Requirements
The power supply range for the
flow controller is 24 VDC ±10%.
The power supply to the unit must
provide clean power and must
be used only to power similar
measurement-type devices.
Storage Temperature Range
The flow controller can withstand
storage temperatures between
-15°C – 40°C (5°F –104°F) with
no permanent effect on the
performance of the device.
Operating Ambient
Temperature Range
The flow controller is designed to
operate in ambient temperature,
cleanroom environments. It is speci-
fied to operate at temperatures of
10°C–65°C (50°F–149°F).
Operating Process
Temperature Range
The flow controller is designed to
operate in process temperatures of
10°C–65°C (50°F–149°F).
Line Pressure
Depending on the operating range
of the flow controller being used,
the system line pressure (measured
at the inlet of the unit) must be
69 kPa – 414 kPa (10 psig – 60 psig)
for operating range option 10 –100%
of full scale flow (“T” code flow
range) or 172 kPa – 414 kPa
(25 psig – 60 psig) for operating
range option 5 –100% of full
scale flow (“Y” code flow range).
Pressure Drop
The flow rate is calculated using
Entegris’ differential pressure flow
technology. Depending on the flow
range of the flow controller being
used, the minimum pressure drop
(inlet to outlet port differential
pressure) required for the unit
is 69 kPa (10 psig) for operating
range option 10 –100% of full scale
flow (“T” code flow range) or
172 kPa (25 psig) for operating
range option 5 –100% of full scale
flow (“Y” code flow range).

ENTEGRIS, INC. USER GUIDE 5
INVUE INTEGRATED FLOW CONTROLLERS, MODELS NT6510, NT6520
Dimensions
NT6510
134.9 mm (5.31”)
137.2 mm (5.40”)
154.9 mm (6.10”)
167.6 mm (6.60”)
C
A
39.4 mm
(1.55”)
53.2 mm
(2.10”)
End View Top View
Side View
5.1 mm
(0.20”)
B
Inlet/Outlet
Port Connection
Dimensions
A B C
1⁄4”117.9 mm (4.64") 17.0 mm (0.67") 187.5 mm (7.38”)
3⁄8”117.9 mm (4.64") 17.0 mm (0.67") 191.0 mm (7.52”)
1⁄2”120.8 mm (4.76”) 17.0 mm (0.67") 195.1 mm (7.68”)
The following fitting size and flow range combinations
are available (Flaretek® and Pillar® unless otherwise noted):
Fitting Size
Flow Range (mL/min)
TL
0–15
TT
0–25
T0/Y0
0–50
T1/Y1
0–125
T2/Y2
0–250
T3/Y3
0–500
T4/Y4
0–1250
1⁄4”Yes Yes Yes Yes Yes Yes Yes
3⁄8”Yes Yes Yes Yes Yes Yes Yes
1⁄2” —————Yes* Yes*
* Flaretek® only.
Note: The operating range for "T" code flow ranges (default) is 10 –100% of full scale flow.
The operating range for "Y" code flow ranges is 5 –100% of full scale flow.
Please consult Entegris for PrimeLock® tube fitting options and custom flow range.
Flaretek Tube Fittings

6 USER GUIDE ENTEGRIS, INC.
INVUE INTEGRATED FLOW CONTROLLERS, MODELS NT6510, NT6520
A
End View Top View
Side View
B
C
Super 300 Type Pillar Tube Fittings
Inlet/Outlet
Port Connection
Dimensions
A B C
1⁄4”117.9 mm (4.64”) 17.0 mm (0.67”) 159.3 mm (6.27")
3⁄8”117.9 mm (4.64”) 17.0 mm (0.67”) 167.1 mm (6.58")

ENTEGRIS, INC. USER GUIDE 7
INVUE INTEGRATED FLOW CONTROLLERS, MODELS NT6510, NT6520
NT6520
End View
Side View
C
B
A
Top View
187.5 mm (7.38”)
170.2 mm (6.70”)
200.2 mm (7.88”)
7.1 mm
(0.28”)
71.1 mm
(2.80”)
7.1 mm
(0.28”)
47 mm
(1.85”)
Inlet/Outlet
Port Connection
Dimensions
A B C
3⁄8” 117.3 mm (4.62”) 15.7 mm (0.62”) 224.0 mm (8.82”)
1⁄2”120.9 mm (4.76”) 18.3 mm (0.72”) 228.0 mm (8.98”)
3⁄4”129.0 mm (5.08”) 23.6 mm (0.93”) 234.2 mm (9.22”)
The following fitting size and flow range combinations
are available (Flaretek and Pillar unless otherwise noted):
Flow Range (mL/min)
Fitting Size
T5/Y5
0–2.5
T6/Y6
0–5
T7/Y7
0–10
T8/Y8
0–20
T9/Y9
0–40
3⁄8” Yes Yes ———
1⁄2”Yes Yes Yes — —
3⁄4”———Yes Yes
Note: The operating range for "T" code flow ranges (default) is 10 –100% of full scale flow.
The operating range for "Y" code flow ranges is 5 –100% of full scale flow.
Please consult Entegris for PrimeLock tube fitting options and custom flow range.
Flaretek Tube Fittings

8 USER GUIDE ENTEGRIS, INC.
INVUE INTEGRATED FLOW CONTROLLERS, MODELS NT6510, NT6520
NT6520
Super 300 Type Pillar Tube Fittings
End View Top View
Side View
B
A
C
Inlet/Outlet
Port Connection
Dimensions
A B C
3⁄8” 117.3 mm (4.62”) 15.7 mm (0.62”) 200.2 mm (7.88”)
1⁄2”120.9 mm (4.76”) 18.3 mm (0.72”) 205.2 mm (8.08”)
3⁄4”129.0 mm (5.08”) 23.6 mm (0.93”) 214.1 mm (8.43”)

ENTEGRIS, INC. USER GUIDE 9
INVUE INTEGRATED FLOW CONTROLLERS, MODELS NT6510, NT6520
Installation
Provided Equipment
Verify:
Remove Unit from the Bag
NOTE: This unit has been assembled
and double-bagged under cleanroom
conditions. To maintain purity, only
open under cleanroom conditions.
CAUTION: Do not tighten the
nuts that protect the tube
connections during shipment.
(See the Prepare Fluid Lines
Section on page 9). Tightening
these nuts without the proper
tubing installed may damage
the unit’s tube connections.
!

10 USER GUIDE ENTEGRIS, INC.
INVUE INTEGRATED FLOW CONTROLLERS, MODELS NT6510, NT6520
Mount the Unit
The flow controller and base
bracket assembly must be
mounted to a solid surface
to ensure stability. Verify the
valve and the electrical cable
are free from mechanical stress
from the surrounding equipment.
NOTE: The flow controller
requires mounting in the
direction of the fluid flow.
Mounting Requirements
The flow controller may be mounted
in any orientation. The unit does not
require straight lengths of tubing at
the inlet or the outlet connection.
Recommended hardware
#10 (M4)
Pan head
#10 (M4)
Flat washer

ENTEGRIS, INC. USER GUIDE 11
INVUE INTEGRATED FLOW CONTROLLERS, MODELS NT6510, NT6520
Mechanical Installation
The standard InVue Integrated Flow
Controller must be used with the
proper tubing size and fittings.
NOTE: For detailed tube flaring
instructions, see ”Flaretek tube fit-
ting flare and assembly procedures”
at www.entegrisfluidhandling.com
(follow the Fittings>Tube Fittings>
Flaretek Tube Fittings links).
For detailed Super 300 Type Pillar
tube fitting assembly instructions,
contact Nippon Pillar Packaging
Company, Ltd.
CAUTION: Over-tightening of
the nuts will result in damage
to the fitting.
!
Flare each tube end
prior to installation
Connec
t Fluid Lines
Process fluid tube
Slide the nut onto the tube
Prep
are Fluid Lines
Process fluid tube

12 USER GUIDE ENTEGRIS, INC.
INVUE INTEGRATED FLOW CONTROLLERS, MODELS NT6510, NT6520
When installing flared tubing to the
flow controller, the flared tube is
pushed over the valve’s fitting until
the fitting reaches the smaller tube
diameter. The amount of torque
required to tighten the nut is depen-
dent upon the size of the fitting.
Flaretek Fitting 1⁄4”3⁄8”1⁄2”3⁄4”
Torque (in•lbs) 5 8 11 14
Torque (N•m) 0.56 0.90 1.24 1.58
Care should be taken when installing
the flow controller to avoid fluid
leaks. Do not use excessive torque or
subject the unit to high heat during
installation. The unit and base
bracket assembly must be mounted
to a solid surface to ensure stability.
Verify the body and the electrical
cable are free from mechanical stress
from the surrounding equipment.
Power Supply Requirements
The power supply range for the
flow controller is 24 VDC ±10%
regulated. The power supply must
provide continuous 1.0 ampere
(nominal) service for each flow
controller installed. The power
supply requirements must be met
at the wire connections or connector
of the flow controller, not only at the
power supply itself.
The power supply to the unit must
provide clean power and must be
used only to power similar measure-
ment-type devices. The power supply
must not be used to power other
inductive loads, such as motors,
relays, or solenoids. These devices
may produce electrical transients
that may affect unit measurements.
An induced power spike, creating an
interruption in power greater than
10 milliseconds in duration, may
cause the unit to reset.
In addition to providing clean power,
the instrumentation signals and
power return lines must not be run
within the same conduit or cable
along with heavy current demands
from motors, charging capacitors
or other inductive loads. This may
cause a voltage change within the
instrumentation signal line, causing
erroneous output readings from the
flow controller. Loss of power will
not cause the loss of any system
parameters or calibration values.
Input Impedance of the
Voltage Setpoint
The input impedance of the voltage
setpoint is 37 kOhm.
Voltage Drop at the 4–20 mA
Setpoint Input
The 4–20 mA input will drop
<5 V at 20 mA. Input impedance
is <250 ohms.
Lift-off Voltage of the 4–20 mA
Output Loops
The minimum lift-off voltage of the
4–20 mA output loops (flow, pressure
measurements) is 12 VDC. The mini-
mum lift-off voltage is the voltage
required at the unit for proper
operation. The maximum load
resistance for a 24 VDC supply is
600 ohms and includes the resis-
tance of measurement devices
and the interconnecting cable.

ENTEGRIS, INC. USER GUIDE 13
INVUE INTEGRATED FLOW CONTROLLERS, MODELS NT6510, NT6520
Output Load Resistance Effects
Using a 24 VDC power supply, the
two 4–20 mA output loops (flow and
pressure) will experience no shift if
the load resistance is 0–600 ohms.
Reverse Polarity Protection
The flow controller is reverse
polarity protected; connecting the
24 VDC power to any wires will not
harm the unit. To operate properly,
the polarity must be correct.
Over-voltage on any Wire (DC)
In the event of accidental applica-
tion of voltage greater than 24 VDC
±10%, the flow controller will with-
stand continuous 30 VDC on any
wire without compromising the unit.
Over-voltage on any Wire (AC)
The flow controller is not designed
to withstand the accidental appli-
cation of 110/220 VAC to any wire.
Application of AC voltage will
damage the unit.
Short Protection
The flow controller will not be
damaged or compromised in any
way if any combination of wires
are shorted together.
Circuit Protection
Fuse the three input power lines to
each individual InVue Integrated
Flow Controller. The three lines are:
• 2-Red/Pin R, +24 VDC (main
power, 1.0 Amp nominal)
• 3-Orange/Pin M, Flow output,
+24 VDC supply
• 4-Yellow/Pin T, Pressure output,
+24 VDC supply
Use a 2 Amp rated, time lag fuse.
A single fuse can be used for all
three input power lines combined,
or individually, as preferred. Place
the fusing on the input power lines to
the unit at the equipment electrical
enclosure to ensure that both the
wiring to the unit and the unit itself
are protected from any over-current
condition. Best practice is to locate
the fuse away from the typical liquid
exposure or harmful vapor areas.
Locating it within the electrical
enclosure shared by the power
supply enables accessibility for
troubleshooting or replacement.
NOTE: Do not power down the unit
until the homing cycle is complete.

14 USER GUIDE ENTEGRIS, INC.
INVUE INTEGRATED FLOW CONTROLLERS, MODELS NT6510, NT6520
Electrical Connections
Pigtail Electrical Cable
Units specified with a pigtail electri-
cal connection are manufactured
with a permanently attached cable.
Table 1 details the wire connections
for the flow controller type with
pigtail electrical cable.
TABLE 1. WIRE CONNECTIONS – PIGTAIL CABLE
Wire Color Marker No. Function
Yellow 4Pressure output, +24 VDC supply
Brown 1Pressure output, 4–20 mA output
Orange 3 Flow output, +24 VDC supply
Blue 5Flow output, 4–20 mA output
Green 9Re-zero input
Pink 11 Setpoint, voltage, 0–10 or 0–5 VDC
Gray 12 Setpoint, common
Tan 10 Setpoint, current, 4–20 mA
Black 8Ground (+24 VDC common)
Red 2+24 VDC
Violet 6Factory use only – do not connect
White 7Factory use only – do not connect
White/Red Dot-Dash 13 Alarm (non-polarized)
White/Red Dot-Dash 14 Alarm (non-polarized)
Pigtail Cable

ENTEGRIS, INC. USER GUIDE 15
INVUE INTEGRATED FLOW CONTROLLERS, MODELS NT6510, NT6520
G-coded Electrical Connector
(Units where the electrical connector type
has a code starting with “G”, e.g., G01.)
Units specified with a G-coded
connector use a Turck®brand,
versafast style, BSMK type, con-
structed of polyurethane with a
nylon coupling nut. The connector
is over-molded onto an electrically
shielded, PVC-jacketed cable.
The pin contacts for the electrical
connection are gold-plated for perfor-
mance and corrosion resistance. The
connector is physically “keyed,”
making it easy to connect to a recep-
tacle. Press it into a receptacle and
turn the threaded coupling nut to
draw the connector and receptacle
together until finger tight. G-coded
connectors to pigtail mating cables
are available. See the Ordering
Information Section of this
user guide.
The following pin diagram and
Table 2 detail the wire connections
for the flow controller type with
G-coded electrical connector.
Mandatory Connections
2-Red/Pin R and 8-Black/Pin E
wires must be connected according
to Table 1, Table 2 and the Wiring
Diagram on page 16. The set-
point must also be connected to
10-Tan/Pin U wire (4–20 mA
setpoint) and 12-Gray/Pin S
wire (common setpoint) or to
11-Pink/Pin G wire (voltage set-
point) and 12-Gray/Pin S wire
(common setpoint). Connect
9-Green/Pin J (re-zero input) to
switched, normally open 24 VDC
±10% main power supply in order
to have the same ground as the
8-Black/Pine E (ground).
NOTE: The 24 VDC connected to
re-zero must be the main power
supply in order to have the same
ground as 8-Black/Pin E. See the
Maintenance Section of this user
guide for re-zero instructions.
Consult Entegris with any questions
about electrical installation.
Unused Connections
The 6-Violet/Pin O and 7-White/Pin P
wires are for factory use only. Do not
connect to power supply or ground.
These wires must remain discon-
nected.
TABLE 2. WIRE CONNECTIONS –
G-CODED CONNECTOR
Pin Color Function
RRed +24 VDC
EBlack Ground (+24 VDC common)
TYellow Pressure output, +24 VDC supply
ABrown Pressure output, 4–20 mA output
MOrange Flow output, +24 VDC supply
LBlue Flow output, 4–20 mA output
JGreen Re-zero input
UTan Setpoint, current, 4–20 mA
GPink Setpoint, voltage, 0–10 or 0–5 VDC
SGray Setpoint, common
OViolet Factory use only – do not connect
PWhite Factory use only – do not connect
CRed w/
blue stripe Alarm (non-polarized)
NGray w/
brown stripeAlarm (non-polarized) A
E
C
G
J
L
M
N
O
PR
T
U
S
Plug Orientation, Face View

16 USER GUIDE ENTEGRIS, INC.
INVUE INTEGRATED FLOW CONTROLLERS, MODELS NT6510, NT6520
Wiring Diagrams
Normally open switch
Power supply
Power supply
Setpoint control signal
Setpoint control signal
4–20 mA
Normally open switch
For re-zeroing
24 VDC ±10%
24 VDC ±10%
0–5 VDC or
0–10 VDC
For re-zeroing
Electrical cable
Electrical cable
09-Green/Pin J
02-Red/Pin R
(+)
08-Black/Pin E
(-)
12-Gray/Pin S
(-)
10-Tan/Pin U
(+)
02-Red/Pin R
(+)
08-Black/Pin E
(-)
12-Gray/Pin S
(-)
11-Pink/Pin G
(+)
09-Green/Pin J
03-Orange/Pin M
05-Blue/Pin L
04-Yellow/Pin T
01-Brown/Pin A
13-Stripes/Pin C
14-Stripes/Pin N
02-Red/Pin R
09-Green/Pin J
06-Violet/Pin O
07-White/Pin P
AV
11-Pink/Pin G
10-Tan/Pin U
12-Gray/Pin S
8-Black/Pin E
InVue
NT6510/NT6520
Flow Controller
Flow
Alarm
Pressure

ENTEGRIS, INC. USER GUIDE 17
INVUE INTEGRATED FLOW CONTROLLERS, MODELS NT6510, NT6520
Optional Connections
To monitor flow rate, apply 24
VDC to 3-Orange/Pin M wire and
measure the 4–20 mA flow output
signal from 5-Blue/Pin L wire.
To monitor inlet pressure, apply
24 VDC to 4-Yellow/Pin T wire and
measure the 4–20 mA pressure
output signal from 1-Brown/Pin
A wire.
These outputs are electronically
isolated from all other circuit
connections. Using a separate
power supply is possible.
Power supply
24 VDC ±10%
Flow display/
measurement device
Pressure display/
measurement device
Electrical cable
03-Orange/Pin M
Flow loop
05-Blue/Pin L
04-Yellow/Pin T
Pressure loop
01-Brown/Pin A

18 USER GUIDE ENTEGRIS, INC.
INVUE INTEGRATED FLOW CONTROLLERS, MODELS NT6510, NT6520
Setpoint Signal Setup
Use the following formulas to adjust
your setpoint signal output device
to match the flow range of the unit.
Repeat the calculations for multiple
control points.
FLOW
6510-T4-F02-B06-K-P1-U3
99999
1/4“Flaretek®
0 –1250 mL/min
Flow Range = 0–1250 mL/min
4 mA or
0 VDC
at 0 mL/min
20 mA or
5 or 10 VDC
at 1250 mL/min
Formulas and Example Calculations