Resources: Respirator Testing & Equipment

Resources: Respirator Testing & Equipment

In the tradition of the lab’s founder, Gary O. Nelson, we see our group as a reference laboratory capable of addressing the most unique problems in atmosphere generation. See below for detailed information on chemical capacity testing and our atmosphere generators.

Chemical Capacity Testing Resources

Vapor Challenges

Vapor Challenge Standard Chemical List

We specialize in chemical challenge testing of respirator cartridges, filters, or any media designed to remove chemical contaminants from an air stream.  The Miller-Nelson Lab is able to test to NIOSH, ASTM, ANSI, and ASHRAE standards, but can also create test atmospheres of unusual contaminants under client specific test conditions.

Chemical vapor challenge agents, include:

  • Acrolein
  • Ammonia
  • Arsine
  • Carbon monoxide
  • Chlorine
  • Chlorine dioxide
  • Cyclohexane
  • DMMP
  • Ethylene oxide
  • Formaldehyde
  • Hydrogen cyanide
  • Hydrogen chloride
  • Hydrogen fluoride
  • Hydrogen sulfide
  • Mercury vapor
  • Methyl amine
  • Nitrogen dioxide
  • Phosgene
  • Phosphine
  • Sulfur dioxide
  • CS, Tear gas
  • CN, Tear gas
  • Toluene
Miller-Nelson Lab Equipment

Price List for Standard Chemical Vapor Challenge Testing

Pricing for challenge testing of cartridges or media includes one set up fee per chemical, and a testing fee per cartridge or media for the challenge. We also perform air resistance for each cartridge tested.

Additional fees may apply for:

  • Media handling/special preparation/tube testing
  • Cyclic breathing simulation
  • Graphing of breakthrough curves
  • Preconditioning, US or EN

Contact Us for our Standard Price List – Chemical Capacity Testing, or request a quote specific to your project. 

Custom Chemical Vapor Challenges

Miller Nelson Services is a reference laboratory capable of addressing the most unique problems in atmosphere generation. We work with many companies and manufacturers to design vapor challenges for proprietary chemicals.  This provides the company with data to ensure that workers or customers are using the appropriate protective equipment when using these chemicals.

Contact us. Let us know your specific chemicals of concern and use conditions, and we will develop a testing program to meet your needs.

Respirator users can also use the Miller-Nelson Lab resources to do simple experiments leading to development of a respirator change schedule, as recommended in 29CFR1910.134.

Lab Request Forms for Chemical Capacity Testing

Miller-Nelson HCS-501 atmosphere generator

Lab Request Forms for Chemical Capacity Testing

When preparing samples to submit for testing, please take a moment to research and define the test conditions required to meet your testing objectives.  These items may be defined in the testing standard that you are attempting to meet, or they may be specific conditions to assist your company with research and development.  To perform the testing, the laboratory requires that the following test conditions be defined on the lab request form:

  • Flow rate for the cartridge or media test
  • Temperature
  • Humidity
  • Challenge concentration of the chemical agent
  • Breakthrough concentration of the chemical agent

If pre-conditioning is required, then the flow rate, humidity, and time duration required for the pre-conditioning needs to be defined, as well.

Below are links to the Lab Request Forms:

Miller-Nelson Lab Request Form – Cartridges/Filters

Miller-Nelson Lab Request Form – Media/Bulk

Atmosphere Generator Resources

HCS-501 Instrument Description & Specifications

Miller-Nelson HCS-501 atmosphere generator

HCS-501 Instrument Description & Specifications


All HCS-501 series systems control ambient +2 to 35° C (or 20 to 35° C with cooling option) and 20 to 85% RH at 25° C.  They come complete with regulators.  All control systems use 120VAC, 50-60 Hz.

The flow, temperature and relative humidity are set to the desired level using direct reading dial potentiometers. Air flow is measured and controlled using an electronic mass flow controller. A temperature humidity sensor measures the actual conditions. The electronic signals from the sensor form a feedback loop to the controller circuit board. This unit activates heaters in a water reservoir and the humidified air stream to attain and maintain the temperature and humidity conditions. Control functions require no operator intervention except for periodic calibration. All parameters can be observed visually on digital panel meters or monitored with a strip chart recorder. Cooling below room temperature can be achieved using cooling option, CP-200.

Download HCS-501 Product Sheet, which includes description, specifications, features & applications.


Relative Humidity Ranges:  30-90% @ 20ºC; 20-85% @ 25ºC; 10-75% @ 30ºC
Temperature Range:  Ambient ± 2ºC—35ºC, without Cooling Option; 20-35ºC with Cooling Option
Air Flow Ranges:  HCS-501-20, 2-20 L/min
HCS-501-50, 5-50 L/min
HCS-501-100, 10-100 L/min
HCS-501-200, 20-200 L/min
HCS-501-500, 50-500 L/min
Custom Flows available, upon request
Warm-up Time:  5-15 minutes
Dimensions:  20” x 20” x 10”
Weight:  40-60 pounds
Power Requirements:  120 VAC, 50-60 Hz
Water Requirements:  Deionized, purified water, ASTM Type I, resistivity > 18 MOhm-cm, very low organics
Compressed Air Supply requirements:  Clean, dry compressed air delivered at a constant pressure of 65±5 psi


HCS-501 Instrument & Accessories Price List

View our HCS-501 Instrument Price List, which includes all flow models, accessories, and replacement parts.

Have an older model HCS-401? Ask about our trade-in program.  We no longer offer service & support on the HCS-401 model, but when you send in your HCS-401 we will discount the purchase of a new HCS-501 instrument.

Contact Us – To request a quote.  Please indicate which model number(s) are of interest to you.  Also, please provide your company name and the shipping address.

Accessories for the HCS-501

Miller-Nelson Equipment accessories

Accessories for the HCS-501

In addition to the Atmosphere Generator, HCS-501, Assay Technology manufactures a line of accessories to enhance the use of the instrument, and assist you with meeting your laboratory’s production goals.

RH Calibration Chamber, Item MN-RHCC: This item holds a saturated salt solution, employs a fan to circulate chamber air over the RH sensor component, and allows for easy calibration of the Temp/RH probe.  Price $310.

Cooling Option, Item MN-CP-200: The cooling option assists with lowering the temperature of the air flow to below ambient temperatures, to approximately 20°C. Price $250.

Solvent Vapor Generator, Item MN-SV-2000: The solvent vapor generator was designed to vaporize liquid components, like formaldehyde, and introduce the vapor to the testing air stream. Price $1969.

Pressurized Water Vessel, Item MN-PWV: This item holds up to 1.5 gallons of water, places it under pressure, for delivery to the HCS-501, as the RH system calls for more water. Price $1255.

Flow Controller Power Supply, Item MN-ADF-2426: Use this power supply with mass flow controllers, when lower flows are required for your experiments. Price $1654.

Operating Manuals for HCS-501 and Accessories

Miller-Nelson Equipment accessories

Operating Manuals for HCS-501 and Accessories

Download the operating manuals for the HCS-501 instrument and accessories: