Pyxis SP-700 User manual

SP-700 Water Multimeter
Operation Manual
March 10, 2018
Rev. C
US Patent: 9612221
Pyxis Lab, Inc.
1729 Majestic Dr. Suite 5
Lafayette, CO 80026 USA
www.pyxis-lab.com
© 2017 Pyxis Lab, Inc.
Pyxis Lab Proprietary and Confidential

The information contained in this manual may be confidential and proprietary and is the property of Pyxis Lab, Inc.
Information disclosed herein shall not be used to manufacture, construct, or otherwise reproduce the goods
described. Information disclosed herein shall not be disclosed to others or made public in any manner without the
express written consent of Pyxis Lab, Inc.
Limited Warranty
Pyxis Lab warrants its products for defects in materials and workmanship. Pyxis Lab will, at its option, repair or
replace instrument components that prove to be defective with new or remanufactured components (i.e.,
equivalent to new). The warranty set forth is exclusive and no other warranty, whether written or oral, is
expressed or implied.
Warranty Term
The Pyxis warranty term is thirteen (13) months ex-works. In no event shall the standard limited warranty coverage
extend beyond thirteen (13) months from original shipment date.
Warranty Service
Damaged or dysfunctional instruments may be returned to Pyxis for repair or replacement. In some instances,
replacement instruments may be available for short duration loan or lease.
Pyxis warrants that any labor services provided shall conform to the reasonable standards of technical competency
and performance effective at the time of delivery. All service interventions are to be reviewed and authorized as
correct and complete at the completion of the service by a customer representative, or designate. Pyxis warrants
these services for 30 days after the authorization and will correct any qualifying deficiency in labor provided that
the labor service deficiency is exactly related to the originating event. No other remedy, other than the provision
of labor services, may be applicable.
Repair components (parts and materials), but not consumables, provided in the course of a repair, or purchased
individually, are warranted for 90 days ex-works for materials and workmanship. In no event will the incorporation
of a warranted repair component into an instrument extend the whole instrument’s warranty beyond its original
term.
Warranty Shipping
A Repair Authorization Number (RA) must be obtained from Pyxis Technical Support before any product can be
returned to the factory. Pyxis will pay freight charges to ship replacement or repaired products to the customer.
The customer shall pay freight charges for returning products to Pyxis. Any product returned to the factory without
an RA number will be returned to the customer.
Pyxis Technical Support
Contact Pyxis Technical Support at [e-mail].

Pyxis SP-700 Multimeter Operation Manual 3
Table of Contents
1Introducing the Pyxis SP-700 Multimeter.....................................................................................4
1.1 Features of the Pyxis SP-700 Multimeter .....................................................................................4
1.2 Specifications ................................................................................................................................5
1.3 Unpacking the Pyxis SP-700 Multimeter.......................................................................................5
1.4 Standard accessories.....................................................................................................................5
1.5 Optional accessories .....................................................................................................................6
1.6 Dual function light shield ..............................................................................................................6
2Using the Pyxis SP-700................................................................................................................7
2.1 Battery installation........................................................................................................................7
2.2 Using the SP-700 control keys.......................................................................................................8
2.3 Turning the SP-700 on and off ......................................................................................................9
3Multiple parameter measurement ..............................................................................................9
3.1 Measurement................................................................................................................................9
3.2 Temperature measurement..........................................................................................................9
3.3 Conductivity temperature compensation...................................................................................10
3.4 High color and turbidity warning ................................................................................................10
3.5 pH measurement ........................................................................................................................10
3.6 ORP measurement......................................................................................................................11
4Calibrating the SP-700...............................................................................................................11
4.1 PTSA standalone calibration (2 point with zero) ........................................................................12
4.2 Conductivity Calibration..............................................................................................................15
4.2.1 Combined calibration procedure........................................................................................15
4.2.2 Standard conductivity calibration (500, 1000, 2500, or 5000 µS) ......................................17
4.2.3 User-defined conductivity calibration procedure...............................................................20
5pH and ORP calibrations ...........................................................................................................23
5.1 pH electrode calibration .............................................................................................................23
5.1.1 One-point calibration..........................................................................................................23
5.1.2 Second-point calibration.....................................................................................................24
5.1.3 Third-point calibration ........................................................................................................25
5.2 ORP calibration ...........................................................................................................................26
6Device information and diagnosis .............................................................................................27
7Device maintenance & cleaning ................................................................................................28
8Replacing the pH and ORP module (Hardware before SN: 170000).............................................30
9Replacing the pH and ORP module (Hardware after SN: 170000)................................................31
10 Bluetooth connection ...............................................................................................................33
11 Calibrate ST-500 with SP-700 ....................................................................................................34
12 REGULATORY APPROVAL ..........................................................................................................36

Introducing the Pyxis SP-700 Multimeter
Pyxis SP-700 Multimeter Operation Manual 4
1Introducing the Pyxis SP-700 Multimeter
The Pyxis SP-700 is a handheld multimeter that measures simultaneously five key parameters in
a water sample:
•pH
•Conductivity
•PTSA (Pyrene Tetrasulfonic acid tetra sodium salt)
The PTSA measurement uses custom signal processing algorithms to compensate for sample
color and turbidity conditions that can cause erroneous readings.
•ORP
•Temperature
•Free Chlorine –TMB Method (Separate Instructions Document Available from Pyxis)
The SP-700 is a cuvette-less device and has two sample cells. Less than 5 ml water sample is
needed to fill the cells for measurement of the five parameters.
1.1 Features of the Pyxis SP-700 Multimeter
The SP-700 includes the following features:
•Breakthrough technology combining PTSA with conductivity / pH and ORP in a single rugged
one-handed meter. Free Chlorine TMB Method function also included in Color Mode.
•Custom pH/ORP modular design with extra-large junction capacity providing increased
service life.
•Easy replacement of the pH/ORP electrode module without the need to open the meter
enclosure.
•Long battery life: 10,000+ readings.
•Self-diagnosis during calibrations.
•Custom product names and tracer/product ratios configurable via Bluetooth-enabled
devices.

Introducing the Pyxis SP-700 Multimeter
Pyxis SP-700 Multimeter Operation Manual 5
1.2 Specifications
Specifications are subject to change without notice. Contact Pyxis ([email protected]) for an updated specification list.
Item
Specification
Analysis
PTSA
0-300 ppb, ±1 ppb or 1% precision
Conductivity
1-15,000 µS/cm with ATC. ±1% or ±1 µS/cm precision
pH
0-14 with ATC, ±0.01 pH unit precision
ORP
±1500 mV, ±1 mV precision
Temperature
0-70° C (32-160° F), ±0.1° C (±0.2° F)
Free Chlorine
0 –2.2ppm (TMB Method –Ask For Separate Instructions)
Storage Temperature
-20° C - 60° C (-4 - 140° F)
Operational Temperature
0° C - 40° C (32 - 104° F)
Sensor Module
pH/ORP, replaceable
Typical Sensor Life
pH/ORP - 2 years
PTSA/Conductivity - 5 years
Protection Grade
IP67, full dustproof and waterproof
Regulation
CE
Display
Color LCD, visible under direct sunlight
Power Supply
4 AA alkaline batteries
Typical Battery Life
10,000 readings
Dimension (L x W x H)
180 x 80 x 32.6 mm (7.06 x 3.15 x 1.30 inches)
Weight
380 g (0.85 lbs), batteries excluded
1.3 Unpacking the Pyxis SP-700 Multimeter
Remove the instrument and accessories from the shipping container and inspect each item for
any damage that may have occurred during shipping. Verify that all items listed on the packing
slip are included. If any items are missing or damaged, please contact Pyxis Customer Service at
[e-mail].
During shipping and storage after production, a sponge wetted with the KCl based pH storage
solution is placed in the pH/ORP cell. Some storage solution may dry out, leaving white
potassium chloride crystals in the surrounding areas of the cell. Please rinse the cell with DI
before use.
1.4 Standard accessories
The following accessories are included in the SP-700 package:
•Four (4) AA alkaline batteries
•Bluetooth USB adapter
The full instrument manual is available for download at www.pyxis-lab.com/support.html

Introducing the Pyxis SP-700 Multimeter
Pyxis SP-700 Multimeter Operation Manual 6
1.5 Optional accessories
The following optional accessories can be ordered from Pyxis Customer Service,
[e-mail]:
Accessory
Item number
Carrying case for SP-700
MA-700
100 ppb PTSA + 1000 S/cm (KCl) combined
standard
MA-1010C
220 mV ORP calibration standard
ORP-220
100 ppb PTSA calibration standard
PTSA-100
200 ppb PTSA calibration standard
PTSA-200
300 ppb PTSA calibration standard
PTSA-300
1.6 Dual function light shield
The SP-700 light shield (figure 1) has two functions:
•It shields ambient light from potentially interfering with PTSA measurement.
•When the multimeter in storage, the rubber gasket on the side of the light shield facing the
pH/ORP cell seals the cell, maintaining a moisture environment for the electrodes.
Figure 1. Light shield in the open position
If the meter is to be stored for more than two weeks, fill the pH/ORP cell with 0.5 ml of the pH 4
buffer solution or any pH electrode storage solution. The sponge wetted with the pH storage
solution in the pH/ORP cell is needed only for long-term storage.

Using the Pyxis SP-700
Pyxis SP-700 Multimeter Operation Manual 7
2Using the Pyxis SP-700
2.1 Battery installation
The SP-700 is powered by four AA alkaline batteries. Typical battery life after replacing a new
battery set is 10,000 measurements, or 10 months. When the battery capacity is critically low,
the SP-700 displays a LOW BATTERY warning for five seconds, and then automatically turns off.
Note: Do not use rechargeable nickel cadmium (NiCad) or lithium batteries in the SP-700. Use
only alkaline batteries.
Replace the batteries to resume operation after a low battery warning. The SP-700 does not
turn itself on automatically after the new battery installation. To turn the SP-700 back on after
new battery installation, press the OK key for one second.
Maintaining SP-700 date and time during battery installation: The SP-700 has a calendar
timer. To prevent the calendar from being reset to the default date and time (01/01/1970,
00:00:00), install the four new batteries within four minutes after the old batteries are removed
from the battery compartment.
The SP-700 date and time is synchronized with your PC automatically when connected with
uPyxis app via Bluetooth adapter.
The SP-700 battery compartment, shown in Figure 2, is on the back side of the instrument.
Batteries are held in place by a cover secured with four Phillips-head screws.
Figure 2. The SP-700 battery compartment

Using the Pyxis SP-700
Pyxis SP-700 Multimeter Operation Manual 8
Use the following procedure to install new batteries:
1.
2. Remove the battery compartment cover by loosening the four screws.
3. Gently remove the old batteries and dispose of properly.
4. Following the positive and negative signs in the compartment bottom, snap four new AA
alkaline batteries firmly into the battery holder.
5. Replace the battery compartment cover and ensure that the sealing O-ring is lying flat on
the battery holder. Note that failure to properly seat the O-ring may result in water damage
to the meter.
6. Fasten the four screws.
2.2 Using the SP-700 control keys
The SP-700 has three control keys, as shown in Figure 3. The left ( < ), right ( > ), and OK keys are
used to launch an action indicated on the LCD screen directly above the keys. Note that the LCD
screen is not a touch-enabled device; the labels above the keys indicate the function associated
with the keys, and functions can be changed in different operation modes.
Figure 3. Control keys and associated functions

Multiple parameter measurement
Pyxis SP-700 Multimeter Operation Manual 9
2.3 Turning the SP-700 on and off
To turn on the SP-700:Press the OK control key momentarily and release.
To turn off the SP-700:Press and hold the OK key for three seconds. Release the OK key when
the LCD display turns off.
The SP-700 turns itself off after 60 seconds without user interaction.
3Multiple parameter measurement
3.1 Measurement
When powered on, the SP-700 is in Measurement mode (as shown in Figure 3, above).
A water sample can be transferred to the measurement cells using a pipette, or the cells can be
filled directly from a sample bottle.
Rinse cells before measurement. Before beginning a measurement, use some of the sample
water to rinse the cells at least three times. Rinsing the surface between and around the cells
helps reduce cross-contamination when measuring multiple samples, especially when switching
to a sample with conductivity/pH/ORP significantly different than the previous sample.
Using the light shield. To measure PTSA, the light shield should be in the closed position. If you
are not making a fluorescence measurement, you can leave the light shield in the open position
without affecting the reading and accuracy of conductivity, pH, or ORP.
Allow five seconds for the SP-700 to reach stable readings for the six parameters. The time
required to reach a stable reading may be slightly longer if the water sample temperature is
significantly different than the environmental temperature at which the SP-700 had been
equilibrated (stored).
For a sample with conductivity in the range of 100 to 6000 S/cm, the measured conductivity
value should be stabilized in the range of 98–102 to 5940–6060 S/cm, respectively. For a
sample containing 100 ppb PTSA, the measured PTSA should be stabilized within the range of
98–102 ppb.
3.2 Temperature measurement
The SP-700 has a 100platinum RTD located in the PTSA/Conductivity cell. The temperature
sensor is individually calibrated in the factory and does not need to be calibrated during use. The
temperature value measured is used in the conductivity temperature compensation calculation
and in converting the measured cell potential to the pH value at the sample temperature.

Multiple parameter measurement
Pyxis SP-700 Multimeter Operation Manual 10
Note that the pH/ORP cell does not have a temperature sensor. You must fill the
PTSA/conductivity cell to measure the sample temperature. If the PTSA/conductivity cell is dry
and empty, the temperature value used in the pH calculation is the ambient environmental
temperature, which may be different from the sample temperature.
3.3 Conductivity temperature compensation
The displayed conductivity value is automatically corrected to the nominal value at the
reference temperature 25.0° C using the sample temperature measured. The commonly used
linear correction equation is used:
Conductivity at 25° C = (Conductivity at Tmeasure) / [1 + 0.02(Tmeasure –25)]
where Tmeasure is the sample temperature in degrees Celsius.
3.4 High color and turbidity warning
The SP-700 has extra channels to measure sample turbidity and color to automatically
compensate for sample color and turbidity interference. If sample turbidity and color values
determined are too high and beyond the compensation range, a PTSA measurement warning is
displayed. In this case, you should filter or dilute the sample for PTSA measurement.
3.5 pH measurement
The SP-700 uses the standard electrochemical cell for the pH measurement. The cell consists of
a glass electrode and an Ag/AgCl reference electrode. Potassium chloride (KCl) electrolyte filling
gel is sealed in the Ag/AgCl electrode.
The amount of reference electrolyte in the SP-700 is significantly larger than that used in a
common laboratory pH electrode. This reduces the chance of the filling solution being diluted or
contaminated and increases the electrode life.
The pH value is calculated from the measured cell potential (EMF):
pH = EMF / S(T) + pHo
S(T) in the above equation is the calibration slope and is theoretically equal to:
0.1986(T + 273.15),
where T is temperature in degrees Celsius.
S(T) has a theoretical value of 59.17 mV at 25o C. pHois the calibration intercept. The calibration
slope S(T) at the nominal temperature 25.00o C and the intercept pHoare determined in the
two-point or three-point calibration procedure. pHois determined as well in the singe-point pH
7.00 calibration.

Calibrating the SP-700
Pyxis SP-700 Multimeter Operation Manual 11
The temperature value measured by the SP-700 is used in the above equation to calculate the
pH value at the measurement temperature. Note that the temperature involved in the pH value
calculation is quite different from the temperature compensation in the conductivity
measurement. The temperature-compensated conductivity value is a would-be value at the
reference temperature 25o C, while the pH value displayed by the SP-700 is the true pH value at
the sample temperature.
3.6 ORP measurement
The SP-700 measures the sample ORP with the platinum electrode and the Ag/AgCl reference
electrode in the pH/ORP cell. An ORP value without specifying the reference scale has no
meaning. The ORP value reported by the SP-700 could be referenced to either the standard
hydrogen electrode (SHE), i.e., in the unit of Eh, or an Ag/AgCl electrode. The value displayed by
the SP-700 depends on the ORP value of the ORP standard used in the calibration.
If the ORP value of the standard is referenced to the standard hydrogen electrode (SHE), the
ORP value reported by the SP-700 is SHE-based, i.e., in the unit of Eh. If the ORP value of the
standard is referenced to the Ag/AgCl (3M KCl) electrode, the ORP value reported by the SP-700
is referenced to the same, commonly noted as mV (Ag/AgCl, 3M KCl).
The ORP electrode is calibrated using the Zobell’s standard using the value of 221 mV at 25o C
before shipping. The default ORP scale of the SP-700 before a user calibration is the Ag/AgCl
(3M KCl).
It is difficult to measure ORP of a field sample accurately and precisely. ORP of water samples
with low conductivity and low redox buffer capacity, such as unchlorinated surface water, is
even more difficult to measure. If the SP-700 is exposed to an extremely high (>600 mV) or
extremely low (< -200 mV) ORP sample, you may have to rinse the pH/ORP cell excessively when
switching to measure a lower redox buffer capacity sample.
For a typical cooling water sample treated with oxidizing biocides, a ± 20 mV accuracy and ± 10
mV precision can be expected.
4Calibrating the SP-700
The PTSA, pH, ORP, and conductivity measurements can be calibrated separately using the
corresponding standards.
PTSA calibration requires the 100, 200, or 300 ppb PTSA standard solution. A standard with
conductivity value 500, 1000, 2500, or 5000 µS can be used to calibrate conductivity. Optionally,
you can use a standard with any conductivity value in the range of 500 to 5000 µS, such as the
commonly used 1412 (or 1413) µS standard, to calibrate the SP-700. For convenience, the SP-
700 can be calibrated using a combined standard with 100 ppb PTSA + 1000 µS KCl conductivity.

Calibrating the SP-700
Pyxis SP-700 Multimeter Operation Manual 12
4.1 PTSA standalone calibration (2 point with zero)
It is highly recommended that you use the PTSA standalone calibration procedure if you want to
achieve higher accuracy for low range PTSA measurements (< 20 ppb). The Combined
PTSA/Conductivity Calibration procedure yields the PTSA calibration slope only and does not
change the zero point (see section 4.2.1).
To use the PTSA standalone calibration procedure:
1. Rinse sample cell with DI water, and then fill the sample cell with DI water. Close the light
shield.
Note: In an emergency, “non-PTSA” water, such as city water, can be used.
2. Power the SP-700 on by pressing the OK key. Allow 5-10 seconds for meter to stabilize.
3. A screen like Figure 4 appears. The unit is actively reading and displaying both PTSA and
Conductivity. The values will be very low if DI water is used. The conductivity value is not
critical, but the PTSA value should be near zero. A low non-zero value (such as 0.2 or 0.4) is
acceptable.
Figure 4
4. Press the key labeled F-Cal (the <key). The first screen of the PTSA calibration appears, as
shown in Figure 5.

Calibrating the SP-700
Pyxis SP-700 Multimeter Operation Manual 13
Figure 5
5. Press the key labeled Zero (the <control key) to set the zero point.
6. After successful zero set, a checkmark symbol appears next to Click Zero Button to confirm
success. The screen also updates to show the Slope steps, as in Figure 6. The Cycle
command replaces the Zero command on the black bar, and the possible PTSA selection is
displayed in red. The default is 100 ppb:
Figure 6
7. Rinse the sample cell at least twice with the desired PTSA standard, and with the
measurement cell near full, close the light shield.

Calibrating the SP-700
Pyxis SP-700 Multimeter Operation Manual 14
8. If the 100 ppb PTSA default is not the desired PTSA for calibration, press the key labeled
Cycle (the <control key) to cycle among the PTSA standards 100-200-300 ppb. The value in
red updates as the setting is changed. Ensure that the value selected matches the standard
actually present.
9. Press the key labeled Slope (the >key) to set the slope of the standard desired and
complete PTSA calibration. If calibration is successful, the screen updates with a second
checkmark for the Slope setting as shown in Figure 7, and the message Calibration Succeed
appears.
Figure 7
10. Press the key labeled Exit (the OK control key) to return to the measurement screen. The
screen is similar to Figure 8. Slight variance in the PTSA value is acceptable. If you press Exit
before the second checkmark appears, the calibration will not be completed and must be re-
done.

Calibrating the SP-700
Pyxis SP-700 Multimeter Operation Manual 15
Figure 8
4.2 Conductivity Calibration
4.2.1 Combined calibration procedure
The combined 100 ppb PTSA and 1000 µS calibration requires the Pyxis PTSA-1010C
PTSA/Combined standard. This procedure calibrates both PTSA and conductivity with the single
standard PTSA-1010C.
1. Rinse sample cell with Combined Standard and close the light shield.
2. Power on by pressing the OK key. Allow 5-10 seconds for meter to stabilize.Press the >> key
to cycle to Conductivity Calibration mode (C-Cal) (Figure 9).
Figure 9

Calibrating the SP-700
Pyxis SP-700 Multimeter Operation Manual 16
3. Press the key labeled C-Cal (the >key). The default conductivity calibration screen appears
(Figure 10), the Combined Calibration. This will calibrate both Conductivity (at 1000 µS) and
PTSA (at 100 ppb) when using the appropriate Combined Standard.
Figure 10
4. Ensure the meter is filled with Combined Standard and press the labeled Calib (the OK
control key) to confirm the desired calibration. A confirmation popup appears as in Figure
11.
Figure 11
5. Press the OK key to execute both conductivity and PTSA calibrations. If Combined
Calibration is successful, the Measured field updates to the Target conductivity value (1000
µS) PTSA value (100 ppb) and shows two checkmarks. The message “Calibration Succeed”
appears in red, as in Figure 12.

Calibrating the SP-700
Pyxis SP-700 Multimeter Operation Manual 17
Figure 12
6. After successful calibration, press and hold the Calib key for three seconds to return to the
basic read screen (Figure 9).
4.2.2 Standard conductivity calibration (500, 1000, 2500, or 5000 µS)
Example based on 1000 µS:
1. Rinse sample cell with the desired conductivity standard.
2. Power on by pressing the OK key. Allow 5–10 seconds for the meter to stabilize.
3. The unit is reading both conductivity and PTSA if the light shield is in the closed position. For
conductivity measurement or calibration, the light shield does not need to be closed.
4. Press the >> key to cycle to Conductivity Calibration mode (C-Cal) (Figure 13).

Calibrating the SP-700
Pyxis SP-700 Multimeter Operation Manual 18
Figure 13
5. Press the key labeled C-Cal (the <key). A screen similar to Figure 14 appears. This is the
default Conductivity Calibration mode, which is a Combined Calibration (see section 4.2.1 ).
Figure 14
6. Use the >key to cycle to the desired calibration, for example, 1000 µS. The Standard
Conductivity selections are 500, 1000, 2500, and 5000 µS. For other conductivity values the
User Defined Calibration mode must be used (see section 4.2.3). When the 1000 µS
calibration is selected the screen appears as shown in Figure 15.

Calibrating the SP-700
Pyxis SP-700 Multimeter Operation Manual 19
Figure 15
7. Press the key labeled Calib (the OK key) to confirm the specific Conductivity calibration
desired. The screen updates as shown in Figure 16.
Figure 16
8. To start the calibration, press the OK key.
9. After successful conductivity calibration, the meter reads the sample and displays the value
in the measured section. A slight variance from the target is acceptable. A message displays
in red: “Calibration Succeed.”The meter display appears similar to Figure 17.

Calibrating the SP-700
Pyxis SP-700 Multimeter Operation Manual 20
Figure 17
10. After successful calibration, press and hold the key labeled Calib (the OK control key) for
three seconds, to return to the basic read (measurement) screen. Return to Read mode is
not automatic, except through a power-off cycle.
4.2.3 User-defined conductivity calibration procedure
1. Rinse sample cell with desired conductivity standard.
2. Power on by pressing the OK key. Allow 5-10 seconds for meter to stabilize.
3. The unit is reading both conductivity and PTSA. The PTSA will be low or zero if the standard
is solely a conductivity one. The conductivity reading should be close but not necessarily the
same as the value of the standard added.
4. Press the >> key to cycle to Conductivity Calibration mode (C-Cal) (Figure 18).
Figure 18. Press the key labeled C-Cal (the > key)