Humidified Tandem Differential Mobility Analyzer (HTDMA)

Model 3100

Features

Most particles in the atmosphere take up water when exposed to increasing relative humidity – this often explains the poor visibility during the early morning hours when the relative humidity is high and particles have swollen in size and more effectively scatter solar radiation. When we inhale particles they also grow into water droplets, how large they grow determines where they deposit in our respiratory systems. Brechtel developed the first commercial version of the Humidified Tandem Differential Mobility Analyzer (HTDMA) so researchers who wanted to explore the complexities of particle water uptake no longer had to build their own instruments, instead they could rely on our 20 plus years of experience with HTDMAs to invest in a solution that would let them focus on their science and not the tool.

If your work requires real-time particle size and relative humidity dependent water uptake and number size distribution measurements, the HTDMA may be the solution for you.

  • Fully automated and field tested
  • Comprehensive, easy-to-use software with experiment scheduler module
  • Large particle performance: up to 2 microns!
  • Rapid RH and particle size changes
  • Fast response barrier-free diffusion-based humidifier
  • Integrated and automated aerosol generation system (optional)
  • Rack mount kit (optional)

Benefits

  • Characterized in peer-reviewed literature
  • Easily integrated with chemical composition measurement devices
  • Years of continuous field deployment
  • Backed by over 20 years of HTDMA measurement experience

Technical Specs

Humidified Tandem Differential Mobility Analyzer

parameter value type
DMA polydisperse flow rate 0.2-2.0 lpm
DMA sheath flow rate 2.5-10.0 lpm
Relative humidity range 2-93 % RH
RH control stability at 80% RH (1σ) 0.5% RH
Time to reset RH set point by 10% <180 seconds
Time to reach 93% RH from 2% <300 seconds
Time to reach 80% RH from 2% <300 seconds
DMA sizing range 0.01-2.0 µm ¹
CPC size range 0.005-2.0 µm
CPC counting range 0.001-105 cm-3
Operating pressure range 200-1000 mb ²
Operating temperature range 15-35°C
SEMS footprint size 48x33 cm
HSEMS footprint size 38x58 cm
Height 64 cm
Total weight 68 kg
HTDMA instrument power 240 watts
Pump power required (@230vac) 650 watts
Operating voltage 100-230 VAC
¹ With HT-DMA2 option
² Only with SEMS-Exp options


Copyright ©2015 All specifications are subject to change without notice. BMI assumes no responsibility for any inaccuracies in this document or for any obligation to update information in this document. BMI reserves the right to change, modify, transfer, or otherwise revise this publication without notice.

Applications and Solutions

  • Aerosol climate impact studies
  • Measurement of hygroscopic growth of rapidly evolving aerosol size distributions
  • Cloud condensation nucleus studies
  • Visibility reduction studies
  • Aerosol health impacts
  • Long-term climate and air quality monitoring
  • Process monitoring
  • Tobacco smoke inhalation studies

Software

The HTDMA software runs on Windows PCs integrated into the instrument and features a graphical user interface with point-and-click operation. A real-time display of particle water uptake is available through plots of measured number concentration versus growth factor or physical size. Data are displayed as raw counts, raw concentration and processed concentration. System overview and detailed operating parameter views make it easy to determine if the instrument is operating within specification. Data is inverted on-line using a simplified inversion process for quickly viewing and analyzing results. An easy-to-use data post processing software tool applies the full HTDMA transfer function to invert raw measurement data accounting for the full instrument response function.

The scheduler feature allows you to pre-define the various experiments, including atomizer runs, you wish to perform and leave the HTDMA unattended while it does your work for you!

What’s Included

The HTDMA comes with the following items:

  • Scanning Electrical Mobility Sizer (SEMS, dry sizer with either 1um or 2um DMA,  external pump package and Mixing CPC)
  • Humidified Scanning Electrical Mobility Sizer (HSEMS) with either 1um or 2um DMA, Diffusion-based Humidifier and Mixing CPC
  • Software to control HTDMA operation, configure experiments & instrument, perform & check calibrations and post-process data
  • Software to allow upstream SEMS to run in scanning mode during HTDMA operation
  • Keyboard, monitor, mouse & KVM switch to connect SEMS and HSEMS computers
  • Rugged Wooden shipping container holding both SEMS & HSEMS

Accessories

The following optional accessories are available:

HTDMA accessories list

Part Number Description
3110 Aerosol pre-humidifier (0.1 to 2 lpm)
8008 Particle Round Jet Impactor (0.5 µm cut size, 0.7 lpm flow)
8009 Particle Round Jet Impactor (1.0 µm cut size, 0.7 lpm flow)
9000 Aerosol charge neutralizer (requires Polomium-210 radioactive sources)
9001 Aerosol non-radioactive charge neutralizer (available late 2017)
9002 Aerosol Soft X-ray Charger
9202 HTDMA Integrated Aerosol Generation System
9200 Aerosol Generation System
HT-DAIR115 External dry air supply, 115V
HT-DAIR230 External dry air supply, 230V
HT-P115 External vacuum pump, 115V
HT-P230 External vacuum pump, 230V
HT-PPSoft Post-processing software to allow off-line inversion of measured raw TDMA count distributions (requires IGOR software for Windows or Mac)
RackH HTDMA rackmount kit for 19" instrument racks
HTDMA-Kit Maintenance Kit for HTDMA


Related Products

Contact us to discuss how Brechtel can help you.

  • We have been operating Brechtel’s HTDMA (Model 3002) in the lab and at our field site since 2010 and have found the staff and Fred himself very helpful and sensitive to our needs, even though we are are located in Hong Kong, quite a long distance from California. The timely responses to our needs over the years have been very important to us and we are very satisfied with service provided by Brechtel.

    Chak K. Chan, Ph.D. Professor, Division of Environment and Department of Chemical and Biomolecular Engineering
    Hong Kong University of Science and Technology