​Model N701H
High Performance Zero Air System​​​


092910740A - MANUAL,USER, N701, N701H.pdfN701/N701H Manual7104 KB
ESD Fundamentals - 04786.pdfFundamentals of Electro-Static Discharge (ESD)216 KB
SAL000076K - Environmental Instruments Overview.pdfEnvironmental Instruments Overview610 KB
SAL000129A - N701H.pdfN701H Specifications916 KB


 Maximum Output 30 SLPM at 30 psig; 10 SLPM at 60 psig​
Dew Point Less than -40ºC
Dryer Regenerative, heatless dryer with lifetime of greater than 5 years
Output Concentration SO2 < 0.025 ppb
H2S < 0.025 ppb
NO < 0.025 ppb
NO2 < 0.025 ppb
NH3 < 0.025 ppb
O3 < 0.3 ppb
CO < 10 ppb  
HC < 0.25 ppb
Compressor Dual-cylinder, internal long-life, oil-less piston pump
Power Requirements 110V-120V, 60 Hz
220V-240V, 50/60 Hz
Operating Temperature Range 5 - 40ºC
Dimensions (HxWxD) 8.75” x 17” x 28” (222 x 432 x 711.2 mm)
Weight 69 lbs (31.3 kg)​
Included I/O

Specifications are subject to change without notice.
All specifications are based on constant conditions.​
1 x Ethernet: 10/100Base-T
1 x RS232 (57,600 baud)
MODBUS Protocol Support


  • Long-life scrubbers
  • ​Regenerative, heatless dryer
  • High performance CO/Hydrocarbon scrubber
  • Trace-level output purity
  • Dew point indicator
  • Modbus connectivity (standard)
  • Automatic pump control & water drain​


The N701H has digital communications including RS232 and TCP/IP with Modbus communications. This allows remote monitoring of key instrument functions including dewpoint status, scrubber temperature, box temperature, and output pressure. Additionally, this digital access provides the ability to remotely disable the internal pump, allowing longer service intervals and less power consumption. The user can also remotely start instrument warmup prior to arrival at the site.

The N701H is a fully self-contained source of high purity zero air for dilution calibrators. It is ideal for use with highly sensitive analyzers in ambient background and trace level applications. The N701H includes a dewpoint sensor, an oil-less and diaphragm-free pump, and scrubbers to remove SO2, NO, NO2, O3, H2S, and NH3, plus a high performance heated converter for effective removal of Carbon Monoxide (CO) and Hydrocarbon gases. The N701H is proven to effectively remove contaminants of interest to concentration levels that are below the detection limits of Trace-level gas analyzers.

The high-capacity, regenerative, heatless dryer removes water and produces output with a dew point of less than -40°C (flow rate of up to 30 SLPM at 30 psig, at sea level). The system's pressure, temperature, and dewpoint values are all continuously monitored, which allows a microcontroller to adjust the pump cycling frequency, valve timing, and heater power for optimal performance.