Cal Check, LLC. header
  • Test Filter Certification Services bullet
  • New and Replacement Filters bullet
  • Test Devices for on stack testing, and off- stack test filters bullet
  • On-site training bullet
11600 Black Horse Run, Raleigh, NC 27613
p: 919.847.1898    f: 919.847.8005    e:

Your Clear Choice
for Opacity Monitor On-Stack Testing

Over 25 years in the business!


Cal Check offers top quality opacity monitor test equipment for a single opacity monitor or an entire CEM network. We are your single source to fill all your on-stack or off-stack opacity testing needs.

Whether you have one monitor or a group of many different brands, Cal Check can supply all your testing needs, and keep your test filters traceable to NIST standards to insure accurate results every time.

Cal Check manufactures the best equipment for easy to use testing, and we are continually developing new equipment to meet industry needs for current and next generation opacity monitors.

Each Cal Check test device mounts easily onto your monitor and locks in place. The test device isolates the monitor from the stack opacity so testing may be conducted while the source is on-line. With only one moving part, changing the iris is simple. These test devices are durable — in most cases they will outlast the monitors.

If you are interested in saving time and expense, contact us and we will provide you with the right test device and filters to meet your job requirements, as well as certify the filters you already utilize.