Model 237D Laser-based Airborne Particle Counters

0.5 µm minimum threshold setting at 1 cfm (0.3µm at 0.1 cfm)
Two size channels
RS-232/RS-485 communications

TODAY'S CLEANROOM REQUIRES constant monitoring in order to ensure high quality standards are met. Using a particle counter with a data acquisition system provides up-to-the-minute information on particles in your cleanroom, as well as data for long-term studies and quality reports to customers or internal departments. The Model 237D is built around our popular 237 series of portable counters based on reliable laser-diode technology. Ideal for fixed monitoring, the Model 237D offers NEMA 4X enclosures (Stainless Steel) for the pharmaceutical and food industries. The Model 237D incorporates a standard LED readout for operator feedback on current room counts. When used in a computer-controlled system, the front panel push buttons are locked out, preventing accidental resetting of sampling parameters while under automatic control.

Standard 237D's include flow loss detection to provide an alert for the loss of central vacuum, and vacuum flow control solenoids to permit computer-control of sample air flow. The counter has a 5 foot cable terminated with a 15 pin "D" connector and a vacuum connection. The flow is controlled with a critical orifice which requires 18 inches of Mercury vacuum minimum to maintain constant flow.

Specifications

Size Channels 0.5, 5.0 at 1.0 cfm OR 0.3, 5.0 at 0.1 cfm (consult factory for additional size channels)
Light Source laser diode (30,000 hours mean time between failure)
Coincidence Loss less than 5% at 2,000,000 particles per cubic foot
Factory Calibration mono-dispersed polystyrene latex spheres (NIST traceable) front-panel LED cal display, and 4 to 20 mA output is zero on cal fail
Flow loss Detector Cal fail and 4–20mA output is zero on flow loss
Zero Count
standard less than one count in 3 min.
optional less than three counts in 1 hour
Display 7-digit LED
Output RS485 for computer, optional 4–20mA, two channels
Sample Time 1 second to 24 hours
Hold Time 1 second to 24 hours
Count Alarms 1 to 9,999,999 counts each channel
Concentration Mode 1 second samples, 1 to 10 averaged, display updated every second; displays count per cubic foot or liter (4–20mA mode only)
Power 9 VDC at 600mA
Enclosures: NEMA 4X, Stainless Steel
Size (NEMA 4X) 15.7" W x 10" H x 4 .7" D
Weight 15 pounds (5.8 kg)
Environment Operating 55–105oF (12 to 41oC ), 20 to 95% relative humidity, noncondensing
Storage -40–160oF (-40 to 70oC), up to 98% relative humidity, noncondensing

Accessories
Isokinetic sampling probes: refer to isoprobes data sheet
Distributed Vacuum Systems
Distributed DC Power Systems

Ordering Guide
When ordering, specify Model 237D and:
Minimum Threshold Setting 0.3µm at 0.1cfm, or 0.5µm at 1.0 cfm
Zero count standard or optional
Output RS485 or 4–20mA (Consult)
Number of Channels 2,3,4,5,or 6