Description
Grason-Stadler GSI 28 Auto Tymp Tympanometer Middle Ear Screening Instrument
The Grason-Stadler GSI 28 Auto Tymp is a benchtop tympanometric screening instrument designed for non-invasive middle ear analysis. It features an integrated thermal printer for on-the-spot tympanogram output and includes a connected probe handpiece for patient testing. This is an older, discontinued model from Grason-Stadler (GSI), a well-known name in audiological instrumentation.
Specifications & What's Included
- Manufacturer: Grason-Stadler (GSI)
- Model: GSI 28 Auto Tymp
- Type: Tympanometer / Middle Ear Screening Instrument
- Form Factor: Benchtop / Portable Desktop
- Integrated thermal printer with paper roll (paper present)
- Test modes: Tympanometry (TYMP), Acoustic Reflex (IPSI and CONTRA), Audiometer
- Stimulus frequencies: 500 Hz, 1000 Hz, 2000 Hz, 4000 Hz
- Front-panel indicator lights: POWER, TYMP, REFLEX, IPSI, CONTRA, AUDIOMETER, STIMULUS
- CHART ADVANCE button on control panel
- Chart output scaled in ml and daPa
- Includes: probe handpiece with coiled cable, power cord
- Known defect: ON/OFF switch is non-functional — unit remains powered on continuously
- Status: discontinued model, sold as-is for parts or repair
Applications
Tympanometers like the GSI 28 are used in audiology clinics, ENT offices, schools, and hearing screening programs to assess middle ear function. Tympanometry measures the acoustic immittance of the middle ear — evaluating eardrum mobility and detecting conditions such as otitis media, eustachian tube dysfunction, and ossicular chain abnormalities. The GSI 28 was a widely used screening-class instrument in the 1980s and 1990s, popular for its combination of tympanometry, acoustic reflex testing, and built-in thermal chart printing in a compact desktop form factor. It was designed for quick, non-invasive screening without requiring a sound booth, making it practical for school hearing programs and general clinical use. Parts, probes, and service expertise for this discontinued model are sought by audiological equipment repair technicians and parts suppliers.
This Grason-Stadler GSI 28 Auto Tymp tympanometer has a known defect: the ON/OFF switch does not function and the unit remains powered on continuously. The unit appears complete and includes the probe with cable and power cord. When powered on, the print head moves and the paper feeds slightly. On the main unit, the POWER and IPSI indicator lights illuminate. On the probe, the bottom yellow light stays solid; touching the probe tip causes the middle green light to blink and then go off, with the bottom yellow light returning to solid. The unit has not been fully tested by our staff, as this requires specialized audiological expertise. It is being sold as-is for parts or repair with no functionality guarantee. Please review all photos carefully and contact us with any questions before purchasing.
Thanks for your interest. Recycled Goods Inc., Ventura, CA.
FDA Regulation and Certification: The sale of this item may be subject to regulation by the U.S. Food and Drug Administration and state and local regulatory agencies. If so, do not purchase this item unless you are an authorized purchaser. If the item is subject to FDA regulation, we will verify your status as an authorized purchaser of this item before shipping.
Upon receipt, it is the BUYER'S responsibility to have this instrument checked and certified for use by a qualified Technician prior to placing it into use or service.
Warranty Information
Additional Information
Brand: |
Grason-Stadler |
Model: |
GSI 28 |
MPN: |
GSI 28 |
Type: |
Tympanometer / Middle Ear Screening Instrument |
SKU: |
21584 |
Seller Notes: |
Includes probe with cable and power cord. Thermal paper roll present. |
Form Factor: |
Benchtop / Portable Desktop |
Printer Type: |
Integrated Thermal Printer |
Test Type: |
Tympanometry, Acoustic Reflex (IPSI, Contra), Audiometer |
Stimulus Frequencies: |
500 Hz, 1000 Hz, 2000 Hz, 4000 Hz |
Reflex Channels: |
IPSI and Contra |
Known Defect: |
ON/OFF switch non-functional — unit powers on continuously |
Country/Region of Manufacture: |
United States |
Compatible With: |
Grason-Stadler GSI 28 probe and accessories |
Application: |
Middle ear analysis, hearing screening, audiology clinic |
Condition Notes: |
Grason-Stadler GSI 28 Auto Tymp tympanometer. Known defect: ON/OFF switch non-functional — unit stays on continuously. Appears complete with probe. Limited power-on observations noted. Not fully tested. Sold as-is for parts/repair. |
California Prop 65 Warning: |
WARNING: This product can expose you to chemicals including lead and lead compounds, and DEHP (a phthalate), which are known to the State of California to cause cancer and birth defects or other reproductive harm. Go to P65Warnings.ca.gov |