TB 9-4920-457-24
IDENTIFICATION AND DESCRIPTION
1. Test Instrument Identification.
This bulletin provides instructions for the
calibration of Pitot and Static Testers, Barfield, Model 1811 Series. The manufacturers'
manuals were used as the prime sources in compiling these instructions. The equipment
being calibrated will be referred to as the TI (test instrument) throughout this bulletin.
a. Model Variations. Models 1811D, 1811E, 1811G, and 1811H are basically the
same. All models have hand operated vacuum and pressure pumps. The 1811H has,
additionally, an internal electric pump with a line cord, fuse, switch, and function switch.
Differences in range are described in the text and table 1. Models 1811D and 1811E do not
have vertical speed indicators.
b. Time and Technique. The time required for this calibration is approximately 3
hours, using the physical technique.
2. Forms, Records, and Reports
a. Forms, records, and reports required for calibration personnel at all levels are
prescribed by TB 750-25.
b. Adjustments to be reported are designated (R) at the end of the sentence in which
they appear. Report only those adjustments made and designated with (R).
3. Calibration Description. TI parameters and performance specifications which
pertain to this calibration are listed in table 2.
Table 1. Model Code Designations
Model 1811D/E or
0
Model 1811G/H
Airspeed indicator
Vertical speed
Altimeter
indicator
0
none
1
50 to 650 knot range
1
---
1
50,000 ft range in. Hg baro scale
2
10 to 150 knot range
2
2000 ft/minute range
2
55,000 ft range in. Hg baro scale
3
10 to 200 knot range
3
3000 ft/minute range
3
---
4
60 to 420 knot range
4
4000 ft/minute range
4
35,000 ft range in. Hg baro scale
5
20 to 200 knot range
5
---
5
35,000 ft range in. Hg/mbar baro scale
6
20 to 250 knot range
6
6000 ft/minute range
6
50,000 ft range mbar baro scale
7
---
7
---
7
35,000 ft range mbar baro scale
