Instech P720 User manual

Model P720 Peristaltic Pump
Operation Manual
NOTE: This pump is a laboratory device. It is
not
intended for use on humans.
Instech Laboratories, Inc. cannot assume liability from improper use of its products.

1
Instech’s Model P720 pump is a full-featured, miniature peristaltic
pump designed specifically for low flow laboratory applications.
Instech’s wide variety of pump tube sets let you configure this
pump to run at flow rates from 0.2 to 180 ml/hr,* to work with a
variety of solutions, and to pump in single or dual channel mode.
The Model P720 can operate as a stand-alone pump or as an ele-
ment in closed loop control applications using the external speed
control input. The pump has an internal battery that will operate
the pump continuously for up to 30 hours if the power should fail
or if you just want to move the pump around your lab without
turning it off.
This pump’s circuitry has been designed to minimize electromag-
netic radiation, making it ideal for use near sensitive microelec-
trodes. For quietest operation, run the pump using the internal
battery.
* For the base model with a 900:1 motor gear ratio. Other motors
are available for other flow rate ranges.

2
Set-up
Check for signs of shipping damage. You should have received:
1....Model P720 pump
1....Wall mounted 15V DC power adapter
1....9V lithium battery
1....3.5mm stereo jack (for external speed control)
Order tube sets separately.
Model P720 pump controls
Battery Installation
1. Place POWER switch in off position (out).
2. Remove screw holding access cover on underside of pump and
remove plate.
3. Withdraw connector and attach to battery terminals. A
lithium U9VL is preferred due to its long shelf life and higher
capacity (about twice the operating time as an alkaline)
although an alkaline will suffice.
Pump runs at full
speed while
pressed
Speed source selector
(set to INT for normal
use)
Power on/off (Red
LED on pump head
indicates power on)
Input for 9VDC power adapter
(does not charge battery)
Fine speed
control
Coarse speed
control
Motor run/stop
Monitor output and external analog control
input – use stereo jack for connection

3
4. Make sure that the removal ribbon is below the battery.
5. Place the battery into the compartment and replace access
plate.
Testing Battery Backup Operation
1. Place speed source selector in INTernal position.
2. With no external adapter attached, turn on POWER switch
and check pump end for illumination of red LED.
3. Press PURGE. The rotor should turn at full speed.
4. Set speed to some value other than zero and turn on motor by
pressing the RUN/STOP button.
5. While motor is running, check that the amber LOW BAT-
TERY LED has not come on (battery voltage below 7.5V); if
so, replace battery.
Pump Tube Installation
1. Slip the tubular portions extending from the bottom of the
connector blocks into the mounting holes with the silicone
tube just above the rotor.
2. Actuate the rotor, using the PURGE button, while guiding the
tubing down and around the rotor with your finger (see figure
below).
3. Press in both connectors so that they align with the square
depressions in the pump.
4. Again press PURGE button to check that the tube has been
correctly installed and that the amber Kapton tape has not
been displaced. There will be slack in the tape as the rotor
turns; this is normal.

4
Pump tube installation
Pump Tube Removal
1. Press the purge button.
2. Lift the input side of the tube out of the holder.
3. As the rotor turns, lift the input side until the entire tube has
disengaged.
4. Remove the output side from its holder.

5
Operation
Stand Alone Operation
1. Insert the power jack into the pump first, then plug the 9V DC
wall mount supply into an AC outlet.
2. Press in the pump POWER switch.
3. Attach inlet and outlet lines as required. Due to the low flow
rates, it is usually best to attach the lines to the pump tube
connector, fill the system, clear any air bubbles, pinch off the
line to stop any flow and then install the pump tube into the
pump as described above. The rotor will prevent flow when it
is not turning. Pump tube installation may be performed
without the external supply if it is more convenient.
4. Set desired flow rate using the two setting control knobs in
conjunction with previously obtained calibration plot of flow
vs. Dial Settings or MONITOR Voltage (see Calibration).
5. Check that SPEED SOURCE is in the INTernal position. If
this switch has inadvertently been moved to the EXTernal
position without an external input the pump will not run or
respond to dial settings.
6. Press MOTOR RUN/STOP button to start pumping. Use this
button to start and stop the pump rather than the POWER; it
provides more rapid starts and stops.
External Speed Control
In this mode you will be supplying an analog voltage to control
the speed of the pump. Bi-directional control is possible using this
mode. The MOTOR RUN/STOP behaves normally. Set the
SPEED SOURCE to EXTernal and apply the voltage via the center
ring of the 3.5 mm stereo phono jack input at the top of the
control panel.

6
Stereo jack connections for EXTernal speed control
The control voltage passes through the speed control potentiome-
ters and can be attenuated via the knob settings. This is a useful
feature when operating more than one pump from a common
control line since it allows individual speed adjustment for each
pump. It is also useful when a digital level is used as a control
voltage.
The input parameters are as follows:
Ensure that maximum MONITOR VOLTAGE (after knob at-
tenuation) does not exceed ±1.75 volts. An input of +1.5V will
produce a MONITOR voltage of about –1.75V when the dials are
at 100 and 10.
Zero volts = Zero flow rate (actively controlled). Note: TTL 0
state may not be 0 volts. CMOS is usually close enough to work
directly.
Positive Control voltage will cause the rotor to rotate clockwise
(outflow will be on the top).
Negative control voltage will cause the rotor to rotate counter-
clockwise (outflow on the bottom).
To establish the maximum dial setting (assuming you desire full
motor speed at your full peed signal):
1. Set Speed Source to EXT.
2. Apply power and press Power Switch IN.
3. Turn dials to 0.
4. Apply the maximum control signal that your system will de-
liver. Increase the dials until the MONITOR voltage reaches a
maximum of 1.75V.
GND
EXTspeed in
input
Monitor voltage
Out.

7
5. You may now perform a calibration of Flow vs. Monitor
voltage as detailed below by either varying the incoming sig-
nal or with a constant input and varying the dials. Remember
not to exceed the values determined in step 4 above.
6. Turn on the MOTOR RUN/STOP switch. You may leave the
switch in this position and stop the pump by applying zero
volts to the control input.
Calibration
Instech’s P720 peristaltic pumps use tube sets of different sizes to
cover the range of flow rates. The base model P720, with a motor
that has a 900:1 gear ratio, will have flows from approximately
0.2 to 180 ml/hr (see chart below). Other models, such as the
P720/66, /10K or /37K will have different ranges as shown in the
spec sheet posted on the Instech website. To determine the flow
rate at a given rotor speed you will need to calibrate your pump.
We have designed our pumps so that the relationship between the
rate setting on the controller and the rotor’s speed is linear;
therefore, in most cases you only need to perform a single-point
calibration. For highest accuracy, we recommend that you
calibrate each pump tube that you use, since tubing ID can vary
from lot to lot.
0
20
40
60
80
100
120
140
160
180
200
010 20 30 40 50 60 70 80 90 100 110
Dial Setting(INTernal speedcontrol)
Approx.FlowRate(ml/hr)
.093" ID
.062" ID
.031" ID
.020" ID
.015" ID

8
1. Attach either the inflow or the outflow tube to a container on
a balance, or one whose weight is precisely known. Ensure
that all the air has been removed from the lines.
2. Set the pump dials to 110 to run the motor at maximum speed
(coarse speed control: 100, fine speed control: 10), and turn
on the pump motor. (Alternatively, when using the external
speed control, or when you need more precision, you may
calibrate vs. Monitor Voltage instead of dial settings. To read
the Monitor Voltage connect a digital voltmeter between
ground and the tip of the 3mm stereo jack plugged into the
monitor jack.)
3. Collect or withdraw a timed sample, typically for 10 minutes.
The total delivered volume upon which the calibration is
based should exceed 0.5 ml (approximately 6 minutes when
using the smallest tubing), assuming that the sample is being
weighed with a resolution of 1 mg.
4. Weigh the sample and calculate the actual flow rate. Flow
rates should be linear with dial settings between 3 and 110.
Tips for Most Accurate Calibration
•Calibrating the pump by measuring the sample in a graduated
pipette is usually less accurate than weighing the sample as
described above.
Scale
Reservoir

9
•When using new tube sets, run the pump at full speed for 20
to 30 minutes to allow the pump tube to stretch into its final
shape.
•Use the same liquid that you will be using under actual oper-
ating conditions.
•When calibrating at very low flow rates, beware of evapora-
tion. Use a covered container or one with a small surface
area.
•If possible, simulate the pressure differences across the pump
tube that will be experienced under actual operating condi-
tions. Increased back pressure on the outflow side will cause a
slight increase in delivery rate due to tubing dilation, though
this effect is usually less than 1%.
Replacement Parts
Kapton Strips
This amber strip can reduce tube wear and minimize the tendency
for the peristaltic action to walk the tube through the pump,
which can stretch the tube and alter the flow rate calibration. The
strip should never be tight around the rotor. Replacement strips
area available—specify part number KSK. In many cases the
kapton strips may not be necessary.
Tube Sets
Tube sets will typically last about one month under continuous
operation. Dual tube sets place greater stress on the pump motor
than do single tube sets, and thus they may shorten the life of the
motor.
To specify a tube set, first choose the size of tube you need based
on your expected flow rates. Next choose the tube material and
inlet and outlet connectors using the table below. When ordering,
give Instech a part number that specifies: inlet connector–tubing–
outlet connector. For example, LL-020S-22 specifies a single
channel .020” silicone tube with a male Luer lock inlet connector
and a 22 gauge hypodermic tubing outlet connector. Note that

10
you can have different inlet and outlet connectors on the same
tube set. Call for current prices.
DUAL TUBE SET WARNING: Dual channel tube sets,
particularly the 062 size, place more stress on the pump motor
than do single channel tube sets, which will shorten the life of the
pump. Pumps with spur gearheads (P720/37K, P720/10K and
P720) are more susceptible to this stress than are pumps with
planetary gearheads (P720/66). In addition, dual 062 tube sets
make contact with the sides of the pump rotor, which will cause
those tube sets to wear faster than other sizes.

11
Available tube set materials, sizes and connectors
Tube size (ID)
Material
Infusate
.015"
.020"
.031"
.062"
.093"
Silicone
Saline, most drugs
015S
020S
031S
062S
093S
C-FLEX®
IV diets with fats
-
020C
031C
062C
093C
VITON®
Petroleum-based fluids
-
020V
-
062V
-
Channel
s
Inlet and outlet connectors
.015"
.020"
.031"
.062"
.093"
Single
22 gauge tubing
22
-
-
-
Single
20 gauge tubing
20
-
-
-
Single
.062" ID barb (soft
plastic)
BS
Single
Male Luer lock
LL
Single
Female Luer lock
FL
Single
.093" ID barb (soft
plastic)
93
Dual
22 gauge tubing
D22
-
-
-
Dual
20 gauge tubing
D20
-
-
-
Dual
.062" ID barb (soft
plastic)
DBS
-
-
VITON is a registered trademark of DuPont Dow Elastomers LLC. C-FLEX is a registered trademark of Consolidated Polymer Technologies, Inc.
Tygon is a registered trademark of Norton Performance Plastics Corporation.
22
22 gauge tubing
20
20 gauge tubing
BS
.062” ID barb
Fits PE50, .020” Tygon® Fits PE100, .030” Tygon® Fits .062” Tygon®
LL
Male Luer lock
FL
Female Luer lock
93
.093” ID barb
Fits female Luer, .093” Tygon® Fits male Luer lock Fits .093” Tygon®
D22
Dual 22 gauge tubing
D20
Dual 20 gauge tubing
DBS
Dual .062” ID barb
Fits PE50, .020” Tygon® Fits PE100, .030” Tygon® Fits .062” Tygon®
Tube Set Connectors

12
Accessories
Instech also offers a range of accessories and replacement parts for
its peristaltic pumps. Call for current prices.
Part Number
Description
P720/RMC
Rod mounting clamp. Attaches P720 and P820 pumps and
controllers to standard rod mounting systems (including
Instech’s UNIMOUNT).
P720/KSK
Kapton strip replacement kit. 20 protective strips, 5
retaining clips and 1 installation tool.
P720/BATT
9V lithium battery for P720 pump.
Specifications
Rotor type
3 roller
Rotor speed
.4 – 14 RPM
Power supply voltage
+8 to 15 V DC
RPM supply sensitivity
–.08 %/Volt
Typical operating current – single tube
25 mA
Typical operating current – dual tube
30 mA
Typical idle current
14 mA
Monitor voltage (INT)
0 to ±1.46 VDC
Nominal external voltage (EXT)
±1.5 to ±10 VDC
Recommended battery
Lithium U9VL
Alternative battery
Standard 9V
alkaline
Battery voltage triggering amber Lo Bat LED
~7.5 V
Size (WxHxD)
2.5”x2.25”x4”
Weight
1 lb
Typical repeatability
±3%
Linearity vs. dial setting
±3%
Accuracy
±5%
Maximum pressure – .015”-.020” ID tube
20 PSI
Maximum pressure – .031”-.093” ID tube
5 PSI
Printed March 2017
7700-05-0070rev01.doc

Instech Laboratories, Inc.
Instech has been a leading provider of
instruments for medical and biological
research for over 40 years. Our reputation
for quality and reliability is recognized by
research facilities, universities and a wide
range of companies throughout the world.
Our design and manufacturing
capabilities include:
•Small fluid pumps
•Continuous animal infusion systems
•Automated blood sampling systems
•Dissolved oxygen measurement systems
•Motor controllers
For more information on the complete line
of Instech systems and custom products, call
us at 800-443-4227 or visit our website at
www.instechlabs.com.
The equipment behind the science.
Instech Laboratories, Inc.
450 South Gravers Road
Plymouth Meeting, PA 19462
800-443-4227 •610-941-0132
FAX [phone]
EMAIL [e-mail]
WEB www.instechlabs.com