HELIUM CALIBRATED LEAK STANDARDSVSLT Sniffer-Detector Calibrators

The VSLT Model CALIBRATORS FOR SNIFFER-TYPE HELIUM
LEAK DETECTORSThe VSLT Adjustable (Variable) Leak-Rate Calibrators havebeen developed specifically to calibrate sniffer leak detectors
and are designed with Teflon-permeation leak rate control
elements to avoid the clogging problems common toCalibrators that have capillary leak elements.
This isparticularly important for small leak rates and industrial use.
The VSLT Accu-Flow™ Calibrated Leaks are available foradjustable leak rates in limited ranges within the usual values
for “Sniffing” of 10-4 to 10-6 atm-cc/sec, as shown overleaf.
VTI calibrates each leak at three pressures/leak rates andprovides a curve of leak rate vs. pressure. Using the curve,
the fill/exhaust valve and the integral pressure gauge (topreserve NIST-traceability), the user changes the Heliumpressure in the VSLT reservoir to obtain the specific leak-rate
desired.

Choosing the VSLT Calibrator

WILL NOT CLOG OR BREAK – has permeation-type leakelement of Teflon®.
ADJUSTABLE LEAK RATES – by changing the pressure.
CAN BE SET TO AN EXACT LEAK RATE – without theusual manufacturing variance.
REFILLABLE RESERVOIR – from the user’s gas supply.
WIDE LEAK-RATE CHOICE – the full range that is used forsniffing.
NO FALSE READINGS - no large dead spaces.
EASY PROBE POSITIONING – for repeatable results.
MEETS ISO REQUIREMENTS - NIST-traceable, A2LAaccredited Calibration Certification.

VTI’s Calibration
Laboratory is Accreditedby the American
Association forLaboratory Accreditation.
VSLT Calibrator
As the major manufacturer of Calibrated Leaks for allgases, all leak rates, and all makes of leak detectors, VTI
supplies them worldwide to users, distributors, and othermanufacturers. These Accu-Flow™ Leak Standards arerecognized internationally for their superior quality
construction and calibration.

The “point-source” design for the gas flow assuresthat excessive Helium gas will not accumulate in“dead spaces”. Any trapped gas causes erroneous
high readings during detector calibration, which can later
result in “passing” bad product.

VACUUM TECHNOLOGY INCORPORATED Oak Ridge, Tennessee USA
Toll-Free: 800-704-4774

Fax: 865-481-3788
sales@vacuumtechnology.comwww.vacuumtechnology.com

HELIUM CALIBRATED LEAK STANDARDSVSLT Sniffer-Detector Calibrators
ORDERING INFORMATIONThe VSLT Calibrators can be ordered for various adjustable leak-rate ranges commonly used for sniffer-typeleak detection. When ordering or requesting a quotation, please provide the Part Number and also specify
the Approximate Leak-Rate Range requested including your preferred leak-rate Units (for example,“approximately 3 to 8 x 10-5 atm-cc/sec”). The Range specification is “approximate” because the minimum
and the maximum value of the range will vary slightly for individual leaks due to the Manufacturing Variance.
The leak-rate range available for each VSLT Leak is limited to somewhat less than a factor of 10, so the leakrate range should be specified as approximately 1 to 6, 3 to 8, or 4 to 9 x 10-x atm-cc/sec.
A leak-rate range extending between two decades can also be requested, such as from 6 x 10-6 up to 3 x 10-5
atm-cc/sec. (This is also an appropriate way to order a VSLT if you want to be able to obtain an exact leakrate of 1.0 x 10-5 atm-cc/sec.) An alternative specification is to identify the “Central Leak Rate” for a VSLT
Leak, such as 5 x 10-5 atm-cc/sec, and VTI will build the Leak to provide that leak-rate at a mid rangepressure on the 400-psig gauge. Using additional calibrations at a lower and higher pressure, the total leakrate range of the Leak then extends above and below this central value. For each VSLT Leak, it is noted thatexact leak rates like 4.5 x 10-5 can be obtained within its available range.
Various leak-rate units can be specified and the calibration data will then be reported in the units requested.
Please contact us for assistance if you have any questions or want a customized VSLT Leak.

“Special Orders” are everyday products for us ! Just let us know what you need !

PART NUMBER BUILD-UP
The VSLT Part Numbers are constructed as follows:

NOTE:

VSLT-X-3C-HE
where X = the code for the Leak Rate “Decade”
within which an adjustable range of leak-rates is being
requested,
where 3C designates three calibration points,
and HE designates that it is a Helium gas leak.

Without requiring specification, the VSLT Model
Calibrator always has a fill/exhaust valve to allow theusers to exhaust gas from its 110 cc reservoir to lower
the leak rate, or to refill the reservoir to a higher pressure(using their clean gas supply) to increase the leak rate.
The 400-psig pressure gauge on the VSLT is used in
VTI’s NIST-traceable Leak-rate Calibrations andpreserves the NIST-traceability of the calibration for theuser as the pressure and leak rate are varied.

The X codes are listed below. As noted above,
the actual range of leak rates requested within thatdecade/range should also be specified.

LEAK-RATE RANGES AND PART NUMBERS FOR VSLT MODEL LEAKS
Examples of requested Leak-Rate Ranges
1 to 6x10-4 atm-cc/sec
6x10-4 to 3x10-5 atm-cc/sec
3 to 8x10-5 atm-cc/sec
6x10-5 to 3x10-6 atm-cc/sec
3 to 8x10-6 atm-cc/sec
4 to 9x10-7 atm-cc/sec

Leak-Rate Code (X)
44/5
55/6
67

Correct Part Number
VSLT-4-3C-HE
VSLT-4/5-3C-HE
VSLT-5-3C-HE
VSLT-5/6-3C-HE
VSLT-6-3C-HE
VSLT-7-3C-HE

VACUUM TECHNOLOGY INCORPORATED Oak Ridge, Tennessee USA
Toll-Free: 800-704-4774

Fax: 865-481-3788
sales@vacuumtechnology.com
www.vacuumtechnology.com
VSLT-DATA-09/2004-Rev1