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​Model T703U

with NumaView™ Software​

​ Trace-Level Photometric Ozone Calibrator



  • Transfer standard for calibration of ozone analyzers
  • Ultra-low ozone capability – down to 3 ppb
  • Large, vivid, and durable color graphics display with touch screen interface
  • Ethernet, RS-232, and (optional) USB com ports
  • Front panel USB connections for peripheral devices and firmware upgrades
  • 12 independent timers for sequences
  • Nested sequences (up to 5 levels)
  • UV Lamp Feedback modes: current control; photometer control
  • Internal zero air pump (optional)
  • Flow adjustable from 1 LPM to 5 LPM (with internal zero air source)
  • Flow adjustable from 1 LPM to 15 LPM (with external zero air source)
  • High Flow/High Output capability (optional)
  • Inlets for external ozone reference sources
  • Two-year warranty



​The following table provides a list of items that  need regular maintenance to ensure your product remains in good working condition.




Cal Check Required

Manual Section

Verify Test Functions

Record and analyze

Weekly or after any Maintenance or Repair



Photometer Pump Diaphragm1

No Replacement Required.  Under Normal Circumstances this Pump Will Last the Lifetime of the Instrument.

Dry Air Pump Diaphragm





Absorption Tube1


As Needed

Yes after cleaning



Perform Leak Check

Verify Leak Tight

Annually or after any Maintenance or Repair



Pneumatic lines

Examine and clean

As needed

Yes if cleaned

 - - -

1 Cleaning of the Photometer Absorption Tube Should Not Be Required as long as ONLY CLEAN, DRY PARTICULATE FREE Zero Air (Diluent Gas) is used
 with the T703U Calibrator ​


ESD Fundamentals - 04786.pdfFundamentals of Electro-Static Discharge (ESD)216 KB
NVS Remote Manual - 08492.pdfNumaView™ Software Remote User Guide867 KB
SAL000073D - T703U.pdfT703U Specification1144 KB
SAL000073D-CN T703U.pdfT703U规格 (Chinese Specification)5220 KB
SAL000076H - Environmental Instruments Overview.pdfEnvironmental Instruments Overview614 KB
T SERIES_6PG.BROCHURE_2018_web.pdfT Series with NumaView™ Software Brochure9567 KB
T703&T703U Manual - 07223F.pdfT703U Manual10486 KB
T703-T703U NVS Manual - 083730703.pdfT703/T703U with NumaView™ Software Manual13060 KB


Linearity ± 1% of full scale
Precision 1.0 ppb
Response Time < 240 seconds to 95%
Stability (7 days) < 1% with photometer feedback
< 3% without photometer feedback (CNST or REF)
​Ozone Generator Module
Flow Rate (with internal zero air source) 1 to 5 LPM adjustable
Flow Rate (with external zero air source) 1 to 15 LPM adjustable
Maximum Output 5 ppm LPM
Minimum Output 15 ppb LPM
Maximum Concentration 5 ppm at 1 LPM
Minimum Concentration 3 ppb at 5 LPM
Response Time < 240 seconds to 98%
​​UV Photometer
Range 0 - 100 ppb to 0 - 10 ppm (selectable)
Precision 1.0 ppb
Linearity ± 1% of full scale
Rise/Fall Time < 20 seconds to 95% (photometer response)
Response Time < 180 seconds to 95% (system response)
Zero Drift < 1.0 ppb/7 days
Span Drift < 1%/24 hours
Lag Time < 10 seconds
Flow Rate 800 cc/min ±10%
​​Electrical Specifications
Power Requirements 100V-120V, 220V-240V, 50/60 Hz
Analog Output Ranges (Test Channel) 10V, 5V, 1V, 0.1V (selectable)
​​Communications Specifications
Included I/O 1 x Ethernet: 10/100Base-T
2 x RS232 (300-115,200 baud)
2 x USB device ports
12 x digital control outputs
12 x digital control inputs
8 x digital status outputs
Optional I/O 1 x USB com port
1 x RS485
Multidrop RS232
​​Physical Specifications
Operating Temperature Range

5 - 40ºC
Dimensions (HxWxD) 7” x 17” x 24” (178 x 432 x 609 mm)

Specifications are subject to change without notice.
All specifications are based on constant conditions.​

35.5 lbs (16.1 kg) with internal zero air pump ​​​​


The Model T703U is a microprocessor controlled ozone calibrator for precision gas analyzers.  Expanded ozone audit levels have created a need for precise ozone calibration well below the capabilities of standard calibrators.  The Model T703U is designed to meet the requirements of ultra-low ozone production.

In addition to a high range with similar performance to the Model T703, the Model T703U has the capability to generate ozone in a low range, or “fractional” mode, for producing ozone levels down to 3 ppb, with exceptional accuracy.  Flow rate and lamp intensity are adjusted to deliver a specified ozone concentration by volume.  The temperature and pressure compensated photometer, identical to that of the Model T400 ozone analyzer, provides feedback control of the UV lamp intensity, assuring stable ozone output.  A nearly unlimited number of calibration sequences may be programmed into the non-volatile memory of the T703U, covering time periods up to a year.

All T Series instruments offer an advanced color display, capacitive touch screen, intuitive user interface, flexible I/0, and built-in data acquisition capability.  All instrument set up, control and access to stored data and diagnostic information is available through the front panel, or via RS232, Ethernet, or USB com ports, either locally or by remote connection.

The Model T703U comes with NumaView™ Software.  NumaView™ Remote PC Software allows for a remote connection with virtual interface and data downloading capability to analyzers operating NumaView™ Software.