Select Blower Range

Principles of Infiltrometer Air Flow Measurement

The Infiltrometer can accurately measure airflow between 18 CFM and 6500 CFM. However, in order to measure accurately over this wide range, the range must be changed as described in the following section.

The Infiltrometer fan blade pushes air out the back of the fan creating a negative pressure in front of the blades. This negative pressure pulls air through the fan's rounded (venturi) shaped inlet. More negative pressure, more flow. The Infiltrometer has been calibrated so for each size of inlet opening and for each negative pressure (Flow Pressure) the flow rate in cubic feet per minute (CFM) is known. As flow decreases the Flow Pressure decreases eventually to the point that it becomes too low to read accurately.

By reducing the size of the inlet with the restrictor plate a given amount of air is forced to enter the blower at a higher velocity, resulting in a much higher flow pressure. (The fan speed must be increased in order to pull the same quantity of air through the blower with the restrictor plate in place.)

Therefore, as the flow rate requirement decreases, such as in tighter buildings, the size of the blower inlet must decrease to maintain a high and accurately readable Flow Pressure. Each inlet size has a pre-established configuration or range. Ranges are somewhat analogous to gears in a standard transmission car. The slower you go the lower the gear.

Changing Ranges

The Retrotec 2000 Series Infiltrometer blower has 7 flow ranges for the greatest possible accuracy and versatility.

Range 22 (wide open with no restrictor plate installed) is the most powerful and most commonly used range. It is used to test buildings with ELA's greater than approximately two square feet.

To use range 22, remove all the restrictor plates.

Range A (1st restrictor ring attached) is the next most commonly used range. It is used to test House/Rooms with ELA's between approximately one and three square feet.

Range B (2nd restrictor ring attached) is used to test House/Rooms with ELA's less than one square foot.

Ranges C8 requires the installation of the plate with 8 holes open, on top of the motor. Ranges C4 down to C1 require plugging some of the holes. Put plugs in the exact positions as shown - others will produce erroneous results. These very restrictive ranges are needed when testing very small rooms.

Each plug must be gently worked into the hole, but be careful you do not push the Panels right out of the doorway. (If the blower is ever turned around for reverse measurement, ensure none of the plugs have fallen out by peeking through the screen.)

2000 Fire Door-Fan Manual

updated 2002-05-28

Page 20 of 58

Page 19 Page 21
Page 20
Image 20
Canon 2000 manual Select Blower Range, Principles of Infiltrometer Air Flow Measurement, Changing Ranges
Page 19 Page 21

2000 specifications

The Canon EOS 2000D, also known as the Rebel T7 in some regions, is an entry-level DSLR that caters to beginners and amateur photographers looking to explore the world of digital photography. Launched as a successor to the EOS 1300D, the 2000D brings a host of features and technologies that make it an appealing choice for those stepping up from smartphone photography.

One of the standout characteristics of the Canon 2000D is its 24.1-megapixel APS-C CMOS sensor. This high-resolution sensor enables users to capture stunningly detailed images with vibrant colors and rich tonal range. Coupled with the DIGIC 4+ image processor, the camera delivers improved performance in terms of image quality, low-light capability, and overall processing speed.

The Canon 2000D features a 9-point autofocus system that includes one cross-type point, helping users achieve accurate focus on subjects. While this autofocus system may not be the most advanced in the market, it is sufficient for general photography tasks, including portraits, landscapes, and even some action shots.

The camera boasts a 3-inch LCD screen, which provides a clear interface for composing shots and navigating settings. Although it lacks a touchscreen, it offers straightforward usability that appeals to novice photographers learning the ropes of DSLR operation. The optical viewfinder with approximately 95% coverage allows users to view scenes through the lens for precise framing.

For those interested in videography, the 2000D offers Full HD 1080p video recording at 30 frames per second. While it may not excel in advanced video features, it provides a solid entry point for hobbyists looking to experiment with video content. The presence of built-in Wi-Fi and NFC capabilities allows for easy sharing of images and remote control of the camera via a smartphone app, enhancing the overall user experience.

Additionally, the Canon 2000D supports a range of Canon's EF and EF-S lenses, providing users with the flexibility to explore various photography styles. Its compact and lightweight design makes it highly portable, making it a great companion for travel and everyday photography.

Overall, the Canon 2000D is a versatile and user-friendly DSLR that strikes a balance between image quality, functionality, and ease of use, making it an excellent choice for those embarking on their photographic journey.
Top Page Image Contents