1. AT 900 / AT 870 General
Goldmann applanation tonometry is the gold standard for accurate and reproducible measurement of the intra ocular pressure.
The AT 900 tonometer fits all Haag-Streit slit lamps and most copies (contact Haag-Streit service for more information on adaptation possibilities). There are special mounts for every Haag-Streit slit lamp available, ensuring the best ergonomic operation of the tonometer on the slit lamp.
The AT 870 tonometer fits most Zeiss-type slit lamps. In its “parked” position it does not interfere with normal diagnostic use of the slit lamp.
Haag-Streit Goldmann applanation tonometers are the most cost efficient solution to measure intra ocular pressure. The competitive price, durability and minimal need for maintenance, paired with the reusable tonometer prisms, ensure a good return on investment. For use with infectious, or other “special”, cases we also offer a disposable prism – “Tonosafe”.

2. Product Selection  Tonometer model Slit lamp model AT 900® C/M
AT 900® M/Q
AT 900® BQ
AT 870
Tonometer model
Slit lamp model
AT 900® C/M
for BD/BC for BM/BMV2)
AT 900® M/Q3)
AT 900® BQ
Hammerscale RAL
AT870
BD 900® / 1)BC 900® 
BM 900® / 1)BMV 900®
BP 900®
BQ 900®
Zeiss and copies
1) Discontinued slit lamp model 2) Also known as model R 3) Also known as model T

3. Goldmann Principle  too light applanation  correct applanation
Measurement of the force necessary to flatten a corneal surface of constant (ø 3.06mm) size
Dial indicator
Force
Pressure 1
9.81 mN
1.33 kPa = 10 mm Hg
 too light applanation
 correct applanation
 too heavy applanation
 decentred

4. Accessories There is an accessory set available including:
Fluorescein paper strips
Pantasept disinfectant fluid concentrated
Instruction manual
Accessories for the AT tonometer series
Set of accessories AT 900® M/Q - C/M - 870
Set of accessories AT 900® BQ
Measuring prism
Box with 10 pads of Fluorescein paper strips
Pantasept concentrate 100 cm3, disinfectant fluid
Pantasept concentrate 1000 cm3, disinfectant fluid
Desinset V, accessories for disinfection of contact glasses
and measuring prisms
Desinset AT, accessories for disinfection of measuring
prisms
How to clean tonometer measuring prisms (WWW – Link) (Open PDF)
List of Haag-Streit approved disinfectants (WWW – Link) (Open PDF)

5. Technical Specification
AT 900® / AT 870
Measurement Principle
Goldmann Applanation: Measurement of the force necessary to flatten a corneal surface of constant (ø 3.06mm) size.
Measuring force generated
AT 900: by leverage weight AT 870: by spring force
Measuring range
0 – 80 mm Hg
Measurement uncertainty of the force on the measuring prism over a measuring range from 0 – mN
0.49 mN  3 s  1.5% of rated value
Reverse span
AT 900:  0.49 mN
AT 870:  0.25 mN
Weight
AT 900 M/Q: kg AT 900 C/M: kg AT 900 BQ: kg
AT 870: 0.850kg