Welch Allyn 9020 Infrared Thermometer

The Welch Allyn Infrared Thermometer model 9020 is a discontinued Welch Allyn product.

It is a tympanic and surface thermometer that gauges temperature by being inserted into the ear canal or being hovered about 1/4 inch above the skin's surface. It works by emitting thermally generated electromagnetic waves, that then radiate heat rays that are read by sensors in the thermometer's probe. Because of this, it is less invasive, and avoids contact with mucous membranes, making cross-contamination less likely.

Infrared thermometers, such as this one, were developed as a result of the discovery of radiation. The first one was patented in 1901, but they didn't become commercially available until the 1930's according to RS Components Ltd's "A Comprehensive Guide to Infrared Thermometers."

The Welch Allyn Infrared Thermometer model 9020 includes a slider at the top that allows for non-contact probe cover placement and removal, and a probe at the tip of the thermometer that is to be inserted into the ear. It also includes four switches, two on each side that allow the user to switch between different modes and settings. On the right side, above the handle and near the screen on the backside of the thermometer is the °F/°C Switch, which allows for the toggling back and forth between the two thermometric scales, and the pulse timer button, which activates the 30-second timer to measure respiration or pulse. Located on the left side in the same position is the mode switch, which allows the user to toggle between the four conversion modes, oral, rectal, core, and surface, as well as the recall button, which redisplays the last temperature taken for 5 seconds on the LCD screen.

To use the thermometer, simply hold it by the handle, (creating an upside down "L" shape with the device,) insert the probe into the ear canal or 1/4 inch above the skin's surface depending on the mode that the thermometer has been placed in, and press the scan button located at the top of the handle, where the handle meets the shaft of the thermometer. A sound will play when the device has completed its reading, and the results will be displayed on the screen facing the user.

Error messages will be displayed on the LCD screen as well, prompting the user if something has occurred with the thermometer. The "Retract Slide" message is indicated by a circle containing a smaller semi-circle in the bottom right. This message is also shown with an audible low beep and prompts the user to retract the probe fully before a temperature can be read, using the slider at the top of the thermometer. The "Malfunction" message is shown as an "X" on the screen. This message pops up when something internally malfunctions. Along with this "X" a numerical error code will also be displayed indicating what the problem is. The two arrows displayed in the top left-hand corner of the screen will only light up if the temperature being read is above or below the thermometer's range (75°F-108°F). The "Low Battery" indicator is depicted as a square with two smaller squares on top. This indicates to the user that they must replace the 4 AAA batteries before they can continue using this device.

This information pertains to the 1996 version of this device.

The Welch Allyn Infrared Thermometer model 9020 is an "L" shaped thermometer that is gray with green accents. Located at the back of the thermometer, furthest from the handle, is an LCD (Liquid Crystal Display) screen that displays information such as temperature reading, operation mode setting (oral, rectal, core or surface), thermometric scale (Fahrenheit/Celsius), as well as error conditions. The model number "9020" is located at top of the handle in a green diamond.

Thermometer Type: Infrared

Measurement Range: 23.9°C-42.2°C (75°F-108°F)

Case Dimensions: 15.38cm x 15.38cm x 5.12cm (6in x 6in x 2in)

Weight (battery and probe covers included): 258g (9.1oz)

Power Source: AAA batteries (4)

Display Type: Liquid Crystal Display

Case Material: ABS Plastic

Operating Environment: 15.6°C- 40.0°C (60°F- 104°F) (70% relative humidity)

Storage Environment: -55°C- 65°C (-67°F- 149°F) (70% relative humidity)

Journal of International Medicine study on non-contact infrared thermometers

More Information on infrared thermometry and its key benefits.