


United Sensor 3 Dimensional Directional
probes measure yaw and pitch angles of fluid flow, as
well as total and static pressures and total temperature.
Each probe has five measuring
holes located on its tip. A centrally located pressure
hole measures pressure P1, while two lateral pressure
holes measure pressures P2 and P3. If the probe is rotated
by a Traverse Unit (Fig. 1) until P2 = P3 as indicated
on a manometer or other sensitive pressure indicator,
the yaw angle of flow is then indicated by the traverse
unit scale (see Manual Traverse Unit catalog pages).
When the yaw angle has been determined an additional
differential pressure P4  P5 is measured by pressure
holes located above and below the total pressure (P1)
hole. Pitch angle is determined by calculating (P4 
P5)/ (P1  P2) and using the calibration curve for the
individual probe (e.g. Curve A, Figs. 2 and 3). At any
particular pitch angle the velocity pressure coefficient
(Pt  Ps)/ (P1  P2) and total pressure coefficient
(P1  Pt)/ (Pt  Ps) can be read from curves B and C,
while Pt  Ps and Ps can be calculated. In the case
of Type DAT probes, a half shielded thermocouple sensor
at the probe tip provides total temperature measurements
at the same point in the stream as fluid pressure and
flow direction measurements.




Fig 1. Typical manometer
connections for DA or DC probes. 

Fig 2.
Typical calibration of DA
probe versus pitch angle. 

Fig 3.
Typical calibration of DC
probe versus pitch angle. 

DA: Five hole prism shaped measuring section.
Measures total and static pressure, yaw angle and pitch
angle. Furnished with individual calibration curves
up to pitch angles of 40? Tip extends 2 diameters beyond
holes. Typical calibration shown in Fig. 4. Smallest
size can be inserted through 1/8" hole. Usable up to
Mach .07. Standard diameters are 1/8", 3/16", 1/4",
3/8", 1.00" 

DAT: Five holes plus thermocouple. Measures
total and static pressure, yaw angle, pitch angle and
total temperature. Furnished with individual calibration
curves up to pitch angles of 40? Tip extends 3.5 diameters
beyond holes. Standard diameters are: 3/16", 1/4", 3/8",
1.00" 




DC:Five hole conical shaped measuring section.
Measures total and static pressure, yaw angle, and pitch
angle. More suitable for use near boundaries than type
DA. Furnished with individual calibration curves up
to pitch angles of 40? Usable up to Mach 0.7. DC120
head fits through a clearance hole .62" diameter. Typical
calibration curve illustrated in Fig. 4. Standard diameters
are: 3/32", 1/8", 3/16", 1/4" 



Ordering Information



Typical Example:
DAT18724F22CDKPlug







