User manual
ALM26 Series User Manual P/N 821644 Rev-A
20
© 2006 Wohler Technologies Inc. ALL rights reserved
Section 3: Technical Information
ALM26 Internal Settings - Address, Peak Hold, PPM Characteristics
LED Bargraph Display Specifications
Level meter type:
Segment quantity:
Level gain (DIP switch selectable):
Bargraph Length:
LED segment size:
LED segment pitch:
Segment display color:
Peak emmision wavelength:
Segment brighness, (If = 20 mA):
Segment brightness, uniformity:
Adjacent segment "Off" brightness:
LED bargraph
26
0, +4, +6, +8 dB
1.078" (27.85 mm)
0.14" x 0.028" (3.57 x 0.7 mm)
0.041" (1.05 mm)
Tri-color (red, amber, green)
Green: 570 nm, Red: 630 nm
3.5 mcd
<10% difference between segments
<1% of brightness of active segment
PPM Characteristics (Ballistics):
The PPM characteristics determine the Integration Time (rise time) and Return Time (fall time) of the level meter. The
Integration Time is the time it takes for the lighted segments of the level meter, after application of a 5 Khz tone at a certain
reference level, to rise within a specified number of dB of that level. Return Time is the time it takes for the lighted segments of
the level meter to fall a certain number of dB after removal of a 5 Khz tone of a certain reference level. The PPM characteristics
available for selection using DIP switch sections 7 and 8 of the 10-position Internal DIP Switch (as shown in the above diagram)
are as follows:
Notes:
1) For level meter Input Reference and Display Mode settings, see pages 12 (Digital) and 14 (Analog).
2) For level meter Addressing, Peak Hold, and PPM Characteristics settings, see this page, below.
3) For level meter Alternate Scales information, see page 21.
12
3
4
56
7
8910
1234
Note: DIP switch is located on Analog Input PCB (919174) or Digital Input PCB (919175) .
ALM26 Internal 10-Position DIP Switch Settings
10
12
21
3
4
56
4
3
8
7
9
10
21
12
4
365
3
4
8
7
9
10
12
12
3456
3
4
879
10
21
12
4365
34
879
1012
12
3456
34
879
Channels 1 to 4
Channels 5 to 8
Channels 9 to 12
Channels 13 to 16
Channels 17 to 20
Channels 21 to 24
6
4
4
4
4
12
3
21
3
12
3
12
3
5
Peak Hold - Off
8657 109
Peak Hold - Manual
Peak Hold - 3 Second
Peak Hold - 10 Second
8
65
7
109
8
65
7
109
8
65
7
109
Address (Factory Set)
5 6
5 6
5 6
Peak Hold (Bargraph Display)
12
3
45678910
Single Sample Return
Time (SSRT)
12
3
12
3
4
56
7
8910
4
56
7
8910
12
3
4
56
7
7
8
8910
DIN 45406
IEC268-10, Type 2
IEC268-10, Type 1
8
7
8
7
8
7
PPM Ballistics (Bargraph Display)
PC (Not Used)
1234567
9
8910
Factory Settings
132 5476 9810
10
RM (Not Used)
Integration Time is 5 ms (-2 dB),
Return Time is 1.7 seconds (20 dB)
Integration Time is 10 ms (-2 dB),
Return Time is 2.8 seconds (24 dB)
Integration Time is 5 ms (-2 dB),
Return Time is 1.5 seconds (20 dB)
Integration Time is a single sample,
Return Time is 1.5 seconds (20 dB)
IEC268-10, Type 1:
IEC268-10, Type 2:
DIN 45406:
Single Sample:
NOTE: The Peak Hold feature (if enabled) will only be visible if a floating segment
is also enabled (see Bargraph Display Modes sections on pages 12 and 14).