Casella Microdust pro Particulate Monitor

Description

The Microdust Pro from Casella USA is a portable, real time monitor for assessing the concentration of suspended particulate matter, and is probably the most versatile instrument available with the ability to measure from 1μgm-3 to 2500 mgm-3. It is the only handheld real-time dust monitor on the market capable of graphically presenting variations in dust concentration on a real time scrolling graph – no longer is it necessary to wait to analyze results on a PC.

Applications
Occupational health & safety monitoring Walk through surveys Site boundary monitoring & environmental measurement Industrial process monitoring Testing respiratory equipment or air filtration efficiency Research activities

Operation and use
	The Microdust Pro measures particulate concentrations using a near forward angle light scattering technique. Infrared light of 880nm wavelength is projected through the sampling volume where contact with particles causes the light to scatter. The amount of scatter is proportional to the mass concentration and is measured by the photo detector. By using a narrow angle of scatter (12- 20°) the majority of light scattered is in the diffracted and refracted components, which minimizes the uncertainty associated with particle color, shape and refractive index. Each Microdust Pro is individually factory calibrated, using a gravimetric technique. The instrument can be returned to this “factory” calibration setting at any time during its life by the use of a non-degradable calibration insert (supplied with every unit). An individual gravimetric calibration is also possible. This involves the simultaneous collection of a gravimetric (filtered) sample of the dust. In this way, two averages are collected over the exposure period. One is from the filter, whilst the other is provided by the averaging function within the instrument. It is then possible to derive the difference in these two figures and correct accordingly. The Microdust Pro features an internal logger that can store up to 15,700 data points over 32 separate runs. The logging interval can be set from 2 seconds to 10 minutes. At 2 seconds, it is possible to record 8.75 hours of data; at 5 minutes, this equates to a total logging time of 50 days. Recorded values include: • Average concentration over the logging period (mgm-3) • Maximum concentration over the logging period (mgm-3) • Date and time stamp Logged results are downloaded to the included MS Windows software package.

Technical Information
Sensing Technique:	Near forward light scattering - 880nm infra red
Ranges:	All instruments provide 0 to 2500 mgm-3 over four ranges as standard:
Resolution:	0.001 mgm-3 (1μgm-3)

Operating Temp Range:

32 to 122 °F (0 to 50°C) non condensing

Storage Temp Range:

-4 to 131 °F (-20°C to +55°C)

Calibration:

Gravimetric method using ‘Arizona Fine’ calibration dust (ISO12103-1, A2)

Zero Stability:

±0.002 mgm-3/ °C

Span Stability:

<0.7% FSD / °C

POWER

Battery:

4 x AA / MN1500 cells - Alkaline or rechargeable NiCad

Operating Duration:

Alkaline (2700mAh) typically >20 hours
NiCad cells (950mAh) typically >10 hours

Battery Charging:

Internal NiCad fast charger circuitry (with time-out protection)

Charge Rate:

Fast charge rate 450mA, Standby charge rate 55mA

Power Adapter:

Universal input voltage range 100-240VAC, 47-63Hz

Output:

12VDC @ 800 mA

GENERAL

Analogue Output:

0 to 2.5 VDC FSD, 500Ω output impedance (3ms update rate)

Keypad:

7 key tactile membrane

Weight:

Instrument only = 34.6 oz (0.97 Kg) (complete kit plus case = 10lb - 4.5Kg)

Dimensions:

Probe = 1.4 Ø x 11.6 in (35mm Ø x 290mm) total length
Instrument H x W x D = 9.8 x 3.8 x 2.0 in (245 x 95 x 50mm)

Maintenance:

Factory cleaning required annually depending on measurement conditions

DISPLAY

Display:

128 x 64 pixel LCD graphics panel with backlight

Displayed Values:

Instantaneous reading:
Other readings:

Rolling average concentration over a user selectable period (1 to 60 sec)
AVE & MAX concentration since power on or reset

Scrolling Graphs:

100 / 200 seconds, 15 minutes or 60 minutes (Y Axis auto-ranging or fixed)

Battery voltage:

Battery Voltage with ‘OK’ / ‘Low’ status message.

CALIBRATION

Factory Calibration:

Traceable isokinetic technique (wind tunnel) and ISO 12103-1

User Calibration:

Four user defined calibration settings available stored for later use.

Routine Calibration:

Firmware calibration for zero & span setting in the field by user.
Optical calibration filter supplied (restores factory calibration)

DATA LOGGING

Internal Memory:

64K EEPROM providing 15,700 data points

Logging Interval:

Adjustable from 2 to 600 seconds.

Recorded Values:

Average, spot, max & min concentration over logging period

Serial Interface:

RS232 up to 38.4K baud

Order Information
Cat. No.	Description
176000A 176093A 103214B 103187B 103182B 151280B 103396B	Microdust pro kit in carrying case with standard accessories Environmental enclosure with pump, adaptor and rechargeable battery pack Gravimetric dust adaptor Aspirated adaptor Respirable dust adaptor Size selective adaptor Iso-kinetic adaptor (for use with stack sampler)