TSI Instruments 3760 User manual

Artisan Technology Group is your source for quality
new and certied-used/pre-owned equipment
• FAST SHIPPING AND
DELIVERY
• TENS OF THOUSANDS OF
IN-STOCK ITEMS
• EQUIPMENT DEMOS
• HUNDREDS OF
MANUFACTURERS
SUPPORTED
• LEASING/MONTHLY
RENTALS
• ITAR CERTIFIED
SECURE ASSET SOLUTIONS
SERVICE CENTER REPAIRS
Experienced engineers and technicians on staff
at our full-service, in-house repair center
WE BUY USED EQUIPMENT
Sell your excess, underutilized, and idle used equipment
We also offer credit for buy-backs and trade-ins
www.artisantg.com/WeBuyEquipment
REMOTE INSPECTION
Remotely inspect equipment before purchasing with
our interactive website at www.instraview.com
LOOKING FOR MORE INFORMATION?
Visit us on the web at www.artisantg.com for more
information on price quotations, drivers, technical
specications, manuals, and documentation
Contact us: (888) 88-SOURCE | [e-mail] | www.artisantg.com
SM
View
Instra

Instruction Manual Model 3760
Condensation
Nucleus Counter
This manual is printed on
cleanroom-compatible paper

II
Part Number 1933760 / July 1991 / Revision C
Copyright ©TSI Incorporated / September 1987 / All rights reserved
Address TSI Incorporated / 500 Cardigan Road / P.O. Box 64394 / St. Paul, MN 55164 / USA
Telex No. 6879024
Limitation of Warranty
and Liability
TSI Incorporated warrants that this product, under normal use and service, shall be free from defects in
workmanship and material for a period of twelve (12) months from the date of shipment to the
customer. This limited warranty is subject to the following exclusions:
1. Batteries, hot wire or hot film sensors are warranted for a period of 90 days from the date of
shipment to the customer.
2. With respect to any repair services rendered, Seller warrants that the parts repaired or replaced will
be free from defects in workmanship and material, under normal use, for a period of 90 days from
the date of shipment to the customer.
3. Seller does not provide any warranty on finished goods manufactured by others.
4. Unless specifically authorized in a separate writing by Seller, Seller makes no warranty with
respect to, and shall have no liability in connection with, any goods which are incorporated into
other products or equipment by the Buyer.
The foregoing is IN LIEU OF all other warranties and is subject to the conditions and LIMITATIONS
stated herein. No other express or implied warranty of fitness for particular purpose or merchantability
is made.
THE EXCLUSIVE REMEDY OF THE USER OR PURCHASER,AND THE LIMIT OF THE
LIABILITY OF SELLER OR ANY OTHER SELLER FOR ANY AND ALL LOSSES,INJURIES,
OR DAMAGE IN CONNECTION WITH THIS PRODUCT (INCLUDING CLAIMS BASED ON
CONTRACT,NEGLIGENCE,STRICT LIABILITY,OTHER TORT,OR OTHERWISE)SHALL
BE THE RETURN OF THE PRODUCT TO THE FACTORY OR DESIGNATED LOCATION AND
THE REFUND OF THE PURCHASE PRICE,OR,AT THE OPTION OF SELLER,THE REPAIR
OR REPLACEMENT OF THE PRODUCT.IN NO EVENT SHALL SELLER BE LIABLE FOR
ANY SPECIAL,INCIDENTAL OR CONSEQUENTIAL DAMAGES.NO ACTION,
REGARDLESS OF FORM,MAY BE BROUGHT AGAINST THE SELLER MORE THAN ONE
YEAR AFTER THE CAUSE OF ACTION HAS ACCRUED.
The purchaser and all users are deemed to have accepted the terms of this limitation of warranty and
liability, which contains the complete and exclusive warranty of the Seller. This limitation of warranty
and liability may not be amended or modified nor may any of its terms be waived, except by a writing
signed by an authorized representative of Seller.
Service Policy Knowing that inoperative or defective instruments are as detrimental to TSI as they are to our
customers, our service policy is designed to give prompt attention to any problems. If any malfunction
is discovered, please contact your nearest sales office or representative, or call TSI's Customer Service
department at [phone].

Contents
iii
About This Manual v
Chapters 1Introduction 1-1
2Setup and Operation 2-1
What you Received 2-
Setting up the CNC 2-
Filling the CNC with Butanol 2-
Flow Control—Vacuum Source 2-
Status Lights 2-
Draining the CNC of Butanol 2-
Counting Single Particles 2-
Viewing Analog Pulses 2-
Correcting for Coincidence 2-
Calibrating the CNC 2-
3Description of the CNC 3-1
4Specifications and Electrical Schematics 4-1
Specifications 4-
Electrical Schematics 4-
Figures 1-1 Back Panel of the CNC
1-2 Advisory Labels
2-1 Front Panel of the CNC
2-2 Inside View of the CNC
2-3 Front-Panel’s Main Circuit Board for the CNC
2-4 Analog Pulse Trace of the Photodetector Signal
3-1 Schematic Diagram of the Cleanroom CNC
Table 1-1 Components of the CNC

About This Manual
v
The Model 3760 Condensation Nucleus Counter Instruction Manual is written for
both the installer and the operator, whether a technician or the head of cleanroom
contamination control.
Organization This instruction manual is organized as follows:
Chapter 1: Introduction
Describes the sensor and gives a brief description of the many features of the
CNC.
Chapter 2: Setup and Operation
Explains how to set up and operate the Condensation Nucleus Counter.
Chapter 3: Description of the CNC
Explains the Basic Operation of the CNC.
Chapter 4: Specifications and Electrical Schematics
Gives the primary specifications of the CNC and provides two electrical
schematics.
Help! To obtain assistance with this hardware, or simply to submit suggestions, please
contact Customer Service:
TSI Incorporated
P.O. Box 64394
St. Paul, MN 55164 USA
Fax [phone]
Telex 6879024
Telephone [phone]

1 Introduction
1–1
The Model 3760 Condensation Nucleus Counter (CNC) operates with the
multisensor Cleanroom Monitoring System (CRMS) using the Model 3701
Multiplexer/Processor or the Model 3704 Single-Channel Processor in conjunction
with an IBM personal computer.
Refer to the CRMS Instruction Manual (P/N 1933700) and the CRMS Advanced
Software Instruction Manual (P/N 930037) for detailed information about the
complete monitoring system. Much of the information in these manuals that
applies to the Model 3755 Laser Particle Counter applies to the CNC as well.
Figure 1-1
TSI Model 3760 Condensation Nucleus Counter
Important Information:
Laser Warnings The CPC is a laser-based instrument. As such, certain precautions must be taken
when using and servicing it. Do not remove any parts unless instructed to do so in
this instruction manual—otherwise you may expose yourself to hazardous optical
radiation.
WARNING: The use of controls, adjustments, or procedures other than
those specified within this manual may result in exposure to
hazardous optical radiation.
Several advisory labels are attached to the components of the counter for your
benefit (see figure 1-2). Reproductions of them, and a note on their locations, are
given below.

1–2 Model 3760 Condensation Nucleus Counter
Figure 1-2
Advisory Labels: a identification label (on the underside); b power requirements label (on
heatsink); c warning label (on the optics housing); d compliance label (on the underside)

2 Setup and Operation
2–1
What you Received The Model 3760 CNC includes the components listed in table 2-1:
TABLE 2-1 Components of the CNC
Qty Description Part No
1 CNC sensor 376000
1 Alcohol fill bottle 2002017
3 ft Tubing, ¼ in. OD x 1/8in. ID 3001257
1 Connector with shutoff valve 1601758
1 Instruction manual 1933760
1 Power-cable assembly (120 V) or 1030817
(240 V) 1030818
Carefully unpack the hardware from its packing boxes. If anything is missing,
contact TSI customer service.
Setting up the CNC To set up the CNC, follow these five steps:
1Operate the CNC only in an upright position.
2Remove the protective caps from the inlet and exit ports and from the electrical
CNC connector.
3Check the label on the back panel to make sure the CNC is set for the proper
line voltage (figure 2-1).
4Plug the enclosed power cord into the CNC connector on the back panel and
then into an AC source. The cord contains a special line filter to reduce both
line noise and the potential for false particle counts.
5Connect a BNC cable to the back-panel connectors so both the CNC and
Multiplexer/Processor (or other counter).
The Multiplexer/Processor (M/P) applies the proper multiplying factors for
calculating the concentration; but first you must set up the M/P sensor selection;
refer to the Model 3701 M/P’s instruction manual.
If you are using a Model 3701 M/P, set the DIP switch 5 for the correct flowrate
according to these two steps:
1To properly display the particle concentration on the Model 3701 M/P, the
3700 ROM version level must be 1.4 or higher. (This is automatically true for
3700s with serial number 165 or higher.) The Model 3700 cannot distinguish
among different types of CNCs (Models 3760 or 3020) so the display will be

2–2 Model 3760 Condensation Nucleus Counter
correct for only one type of CNC if more than one type is used. DIP switch 5
must be off for the Model 3760; switches 5 and 7 must be on for the Model
3020.
2Switch on the CNC once you connect power. If the CNC reservoir is filled with
butanol, the CNC starts sampling and counting particles when you connect the
vacuum.
The measured concentration is displayed on the M/P and/or on the computer.
However, this measurement will not be accurate until the instrument has
reached thermal equilibrium (as indicated by a green status light; see “Status
Lights” below).
Filling the CNC with
Butanol Fill the supplied bottle with reagent grade n-butyl alcohol (butanol).
WARNING: Butanol is flammable and may be toxic if inhaled in sufficient
quantities. Use it only in a well-ventilated area. Its vapor is strong
and foul. If you smell butanol and develop a headache, faintness or
nausea, leave the area at once. Ventilate the area before returning.
The alcohol will not drain from the connector unless it is connected to the mating
part of the CNC. Loosen the bottle cap to provide an air vent; then connect the
fitting to the CNC mating fitting as shown in figure 2-1. Hold the bottle above the
CNC to allow liquid to flow into the CNC and observe the liquid level through the
window on the front panel. When the liquid level reaches the center of the
window, disconnect the filling tube.
Caution: Do not overfill the bottle.
The CNC contains an automatic shutoff valve to prevent overfilling the reservoir.
However, this feature is not intended to be used for connecting the fill bottle for
continuously replenishing alcohol from the fill bottle into the reservoir. Always
disconnect the filling tube once the reservoir is full.
If you are running the CNC continuously, make sure the alcohol in the reservoir is
replenished about twice per week. It is better to keep some alcohol in the CNC’s
reservoir at all times rather than to allow it to dry out between refills. This helps
prevent air from leaking into the sample airstream from the reservoir and generate
stray particle counts.

Setup and Operation 2–3
Figure 2-1
Back Panel of the CNC: afill connector, bdrain connector, cvacuum exhaust, dpower
Flow Control—
Vacuum Source
*Flexible 1/2-inch OD and
1/4-inch ID tubing is recommended.
The CNC flow, controlled by a critical orifice inside the instrument, requires an
external vacuum source, such as the plant vacuum or central vacuum or a vacuum
pump outside the clean area. Connect the vacuum tubing* between the vacuum
source and the exit port on the back panel of the CNC. The CNC requires a
minimum vacuum pressure of 18 inches of mercury and draws a total flowrate of
0.1 scfm. Only 0.05 cfm makes up the sample flowstream. The remaining airflow
is purge air for the cabinet.
To measure the instrument’s flowrate, connect a low-pressure-drop flowmeter to
the CNC’s inlet. A bubble meter or thermal flowmeter (such as TSI’s Model
2011B) works best. The flowrate should be 0.05 cfm (1.415 L/min) ±10 percent. If
the flowrate is too low, the orifice may be plugged, the vacuum may be less than
18 inches of mercury, or the pressure drop of the test flowmeter may be too high.
If you suspect a clogged orifice, contact TSI to learn how to correct this.
Caution: If you are using a vacuum pump, the vacuum exhaust containing
malodorous butanol vapors should be channeled to a hood ventilator
or to an absorbent. Do not exhaust the vapors into an unventilated
area.

2–4 Model 3760 Condensation Nucleus Counter
Status Lights There are two status lights on the front panel of the CNC (figure 2-2). The top light
flashes red each time a particle is detected. The bottom light is either red or green.
Red means that while power is being
supplied to the instrument, the instrument is not thermally stable or else the laser is
malfunctioning. Green means that the condenser is cold enough and that the laser
is operating properly.
On initial power-up, the CNC takes about 20 minutes to reach thermal stability.
Note that the status light does not indicate whether there is flow through the
instrument or whether the flow is correct.
TSI
ALCOHOL LEVEL
FILL
TO LINE DO NOT OVERFILL
INLET
MODEL 3760
PARTICLE
STATUS
PRESENT WHEN LIT
ON WHEN GREEN
CONDENSATION
NUCLEUS
COUNTER
Figure 2-2
Front Panel of the CNC
Draining the CNC of
Butanol Draining the CNC is essentially the same as filling it. Follow these three steps:
1Connect the drain tube that runs to the lower connector on the back panel of the
CNC (figure 2-1).
2Loosen the cap on the fill-bottle and hold the bottle below the instrument.
3Tip the CNC toward the connector to drain the last drops. Even after draining
by gravity, keep in mind that much alcohol will remain soaked in the saturator
block.
To dry the block faster and more completely, first seal off the vacuum exit tube
and the purge-air inlet. The purge-air inlet is inside the cabinet next to the optics
(see figure 2-3).

Setup and Operation 2–5
Figure 2-3
Inside View of the CNC; a Purge-Air Inlet and Filter
The purge inlet tube has a porous plastic filter on one end. Remove the filter and
insert a plug. Be sure that the drain connector from the bottle is attached to the
mating connector on the CNC; it functions as an air escape. Very carefully
introduce slight pressure into the instrument with a clean (filtered), dry,
compressed-air source. The pressure forces the liquid out of the saturator block
and out through the drain. With about 5 psig of air pressure, the saturator will dry
out in a few hours. Vent the air from the drain tube into a hood or other ventilator.
You can also dry the saturator block by draining the liquid and then drawing dry
air through the instrument with the vacuum source for 24 to 48 hours.
If you plan to leave the CNC power off for more than two days, drain the alcohol
from the CNC. It is not necessary to dry the alcohol from the saturator block
unless you are shipping the instrument. Moreover, moving the instrument from
room to room does not require the CNC to be drained, provided you keep it
upright during the process.

2–6 Model 3760 Condensation Nucleus Counter
Counting Single
Particles When connected to the M/P, the maximum concentration that can be measured is 10
million particles per cubic foot (353 particles/cm3). The digital pulses emitted
through the BNC connector on the back panel are 15 volts for 6.4 microseconds. The
maximum output frequency is limited
to 17 kilohertz. The CNC can measure up to 104particles per cubic centimeter
with only 6 percent coincidence, but the particles must be counted with the Single-
channel Processor (Model 3704) or some other “event” counter.
To enable the electronics to measure high concentrations, first remove the CNC
cover. Locate the red toggle switch on the front panel’s main circuit board (figure
2-4). Set it to the position marked “other.” The digital pulses from the BNC
connector are now output at 15 volts for approximately 0.25 microsecond. The
frequency of pulses is not restricted electrically; the higher the output frequency,
the greater the coincidence level (see “Correcting for Coincidence” below). The
switch must be set to “3700” to operate with the M/P.
Viewing Analog Pulses You can observe the analog electrical pulses from the photodetector on an
oscilloscope. Connect the two test pins with a jumper, TP1 and TP2, as shown in
figure 2-4.
The minimum pulse amplitude is about 200 millivolts and the pulse width is about
0.25 microsecond. The pulse amplitudes may range as high as 600 millivolts. The
electrical noise level is about 10 millivolts, giving an overall signal-to-noise ratio
of better than 20:1. Figure 2-5 shows a typical pulse trace on a digital oscilloscope.
Correcting for
Coincidence The CNC counts single particles, such that each particle scatters a separate pulse of
light. At high concentrations, two or more particles are occasionally in the viewing
volume at the same time. The pulses they
generate overlap and are counted as one particle. The frequency of this event
depends on the particle concentration. Within limits, TSI can determine a
correction for coincidence.
The coincidence correction is particularly important at high concentrations. For
most of the range, especially in clean air, the coincidence effect is insignificant. At
a concentration of 35 particles/cm3(1,000,000 particles/ft3), the coincidence error
is only 0.02 percent. At a concentration of 1 x 104particles/cm3(2.8 x 108/ft3), the
coincidence error is 6 percent.

Setup and Operation 2–7
Figure 2-4
Front-Panel’s Main Circuit Board for the CNC; Viewed from the Back
For maximum accuracy, compute the actual particle concentration according to the
following equation:
Na= Niexp (NaQ t)
where Na= the correct concentration (particles/cm3)
N
i= the indicated concentration (particles/cm3)*
Q = 46.7 cm3/s
t = 0.25 microsecond is the effective time each particle resides in
the viewing volume
The Nain the exponent can be approximated by Ni.
Calibrating the CNC Apart from the optics alignment, the initial factory checkout of the electronics, and
the periodic flow verification, the CNC requires no calibration. The flow is
controlled by a critical orifice, and thus, no

2–8 Model 3760 Condensation Nucleus Counter
adjustments are needed. The minimum detectable particle size is controlled by the
supersaturation ratio of the butanol vapor in the condenser. Since the butanol
droplets grow to nearly the same size, there is no particle size discrimination by
electrical pulse-height measurement. Particle detection is unaffected by slight
degradation in laser power or dirty optics. Finally, since the CNC is a single-
particle counter, there is no photometric calibration for concentration.
Figure 2-5
Analog Pulse Trace of the Photodetector Signal While the CNC Samples Ambient
Laboratory Room Air. The bottom trace is a 100x expansion of one of the pulses from the
top trace. The pulse on the bottom trace is approximately 320 millivolts in amplitude and
0.25 microsecond wide.

3 Description of the CNC
3–1
The Model 3760 CNC measures the number concentration of particles that
measure 0.014 micrometer in diameter and larger. The particles are detected by
condensing n=butyl alcohol vapor onto the particles, causing them to grow into
droplets. The droplets are easily counted by a simple optical particle detector.
The CNC is small, quiet and clean; it is designed to be operated continuously with
the Model 3701 Multisensor Cleanroom Monitoring System.
Figure 3-1
Schematic Diagram of the Cleanroom CNC
The sample flow is drawn into a saturator where n-butyl alcohol (butanol)
evaporates into the sample stream. Although the saturator portion is not heated, it
tends to be several degrees above room temperature. The sample then cools by
thermal diffusion in a cooled condenser tube. The butanol vapor becomes
supersaturated and condenses on the particles. A thermoelectric device, cools the
condenser, which is sandwiched between the condenser and a heatsink. The
temperature of the condenser is based on the temperature of the saturator. The
particles are detected by a simple single-particle-counting, laser-diode, optical

3–2 Model 3760 Condensation Nucleus Counter
detector; its flow is controlled with a critical orifice and maintained by an external
vacuum source.
The heatsink, which makes up the entire back panel of the CNC, dissipates heat by
natural convection. Fans are not used because they could contaminate the
surrounding area. Operate the CNC so that the heatsink is exposed to the cooling
ambient; avoid using the CNC in a tightly-closed space.
The cabinet purse airflow (0.05 cfm) helps to cool the electronics within the
cabinet and creates a slight negative pressure within the instrument. Particles that
may be generated inside the cabinet are quickly carried out through the vacuum
line and do not contaminate the surrounding area.

4 Specifications and Electrical Schematics
4–1
Specifications The following specifications—which are subject to change—describe the most
important data of the major components.
Sample flowrate 1.41 L/min (0.05 cfm)
Total exit flowrate 2.83 L/min (0.1 cfm)
Vacuum source minimum 18 in. Hg (0.1 cfm)
Particle size
>0.01 µm
Working fluid n-butyl alcohol
Light source laser diode
Analog pulse signal
typical 200 mV 0.25 µs
Signal-to-noise ratio 20:1 minimum
Digital output
square pulse (M/P 3701)
square pulse (single-channel
processor or other counter)
15 V (6.5 µs)
15 V (0.25 µs)
Concentration (M/P 3701)
(single-channel processor or
external counter)
0 to 10 million ft3
0 to >2.8 x 108 ft3
Size (HLW) 140 x 155 x 220 mm
5.5 x 6 x 8.5 in.
Weight 4 kg (8 lbs)
Power
100/120/220/240 VAC 50–60 Hz
Electrical Schematics The electrical schematics are no. 9060148 (sheets 1 and 2).