ADM-870 05/23/08
12
5.0 USING THE AIRDATA MULTIMETER
The meter is automatically set to read in English units and local density. The SHIFT key must be pressed,
followed by the desired units or density key, to shift the meter into either the metric units function, the standard
density function, or both. The meter will revert to English units and local density each time it is turned off.
After being turned on, the meter will flash a full set of eights to test the display, and will display CAL while
performing a brief internal calibration test. If the FlowHood flaps plug is plugged into the meter, the meter will
display FLO-HOOD and then CF: READ. If the flaps plug is not plugged in, the meter will display DIF PRES and
then IN: READ and is then ready for differential pressure measurements. The functions shown in the lower dark
colored section of each key may be activated directly by pressing the desired key. The SHIFT key must be
pressed prior to the selection of any of the functions shown in the light colored upper half of each key. When
the MODE key is pressed, the selected function will be briefly displayed, immediately followed by display of the
two letter abbreviation for the function being used, combined with READ; for example, CF: READ.
After the READ key is pressed, the selected function will again be briefly displayed. READING will be displayed
during the measurement period, followed by CALC during the calculation period. Then the measurement result
will be displayed.
Each successive measurement is triggered by pressing the READ key, which also clears all previous data from
the display. The meter remains in the previously selected units and function.
The meter will turn off automatically if it has not been used for eight consecutive minutes, except when readings
have been entered into memory; or if performing measurements in the SPEED-READ mode or the automatic
reading mode.
5.1 AUTOMATIC READINGS
Automatic sequential readings are initiated by first pressing the function and units keys required, then pressing
the SHIFT key and the AUTO/READ key. The meter will display AUTO RDY. Pressing the READ key starts
the actual measurement process. The automatic reading sequence may be interrupted by holding the READ
key down until the reading in process has been completed. Release the READ key when HALT is displayed.
The automatic reading sequence will be resumed if the READ key is pressed again when the display reads
HALT. The automatic reading function may be exited by pressing the SHIFT key, followed by the CLEAR key.
5.2 MEMORY/AVERAGE/TOTAL FUNCTION
The memory/average/total function may be used with any of the measurement modes and allows the storage
of up to 100 individual readings for later recall of each reading, the average and sum of the readings. This
capacity may be used to facilitate such tasks as pitot tube duct traverses, VelGrid face velocity measurements,
and the recording of outlet readings. These functions also assist in the averaging of coil face velocities and
temperatures, static pressures, and pressure drop readings.
The STORE key is used only with the memory related functions and serves several purposes. The STORE key
is first used to place the meter in the memory function, and then is used to alternately display the average and
the sum of the readings, after the readings have been entered into memory. This key is also used to interrupt
the memory entry process. The last reading of a sequence is entered into memory by pressing the STORE key.
The memory is cleared by pressing the SHIFT key and then the CLEAR/STORE key.
5.2.1 MEMORY OPERATION
Press the MODE key. The meter will flash the selected function followed by a READ prompt. Press the STORE
key (MEM key prior to April, 1993). The meter will display STOR RDY. When the READ key is pressed, the
meter will display the selected function during the measurement. (If the TemProbe is not in place during flow
or velocity measurements, the meter will flash STD 70
/
F prior to the display of the result). When the READ key
is pressed again, the reading that is on display will be entered into memory as the next reading is being taken.
The meter will briefly flash the sequence number of the reading being placed in memory. A reading will not be
entered into memory until READ is pressed for the next reading, or STORE is pressed to interrupt the sequence.
The reading and memory entry process will continue as long as you continue to take readings. When the
reading shown on the display is the last reading desired, or if you wish to check the average and sum to that
point, press the STORE key. The last reading will be entered into memory, and the number of readings that
have been taken, along with the average of the readings will be displayed: such as 07:395. The first two digits
are the number of readings taken (reading 100 is displayed as 00:nnn). The digits following the colon are the
average of the readings. Press the STORE key again to display the sum of the readings. The number of
readings in memory will not be displayed with the sum. The measurement sequence may be resumed by
pressing the READ key, and may be interrupted at any point by pressing the STORE key.
Summary of Contents for Airdata ADM-870
Page 25: ...ADM 870 05 23 08 21 6 4 VELGRID ASSEMBLY...
Page 34: ...ADM 870 05 23 08 30 FIGURE 10 2 FLOWHOOD IN CASE FIGURE 10 1 FRAME STORAGE...
Page 35: ...ADM 870 05 23 08 31 FIGURE 10 3 FLOWHOOD ASSEMBLY...
Page 37: ...ADM 870 05 23 08 33 FIGURE 10 7 1X5 FRAME ASSEMBLY FIGURE 10 8 3X3 FRAME ASSEMBLY...
