DTX-MFM/SFM Fiber Modules
Users Manual
Using Mandrels for Testing Multimode Fiber
You should use mandrels when testing multimode fiber
with the DTX-MFM fiber modules. Mandrels can improve
measurement repeatability and consistency. They also
allow the use of LED light sources to certify 50 µm and
62.5 µm fiber links for current and planned high bit-rate
applications, such as Gigabit Ethernet and 10 Gigabit
Ethernet.
The gray mandrels included with the DTX-MFM are
compliant with TIA/EIA-568-B for 62.5
µ
m fiber with a
3 mm jacket. Mandrels for 50
µ
m fiber are available from
Fluke Networks. Refer to the appropriate standard for
mandrel requirements if you follow other standards.
Table 1 shows a partial list of mandrel requirements for
TIA and ISO standards.
Figure 3 shows how to wrap the fiber around a mandrel.
Place mandrels on the tester’s output fibers, as shown in
Figures 6 through 13.
In the reference and test connection diagrams shown on
the tester, mandrels are indicated by a loop in the fiber.
Table 1. TIA/EIA-568-B.1 and ISO/IEC TR 14763-3 Mandrel Requirements
Fiber
core size
Standard
Wraps Around
Mandrel
Mandrel Diameter for
250 µm Buffered Fiber
Mandrel Diameter for 3 mm
(0.12 in) Jacketed Cable
50 µm
TIA/EIA-568-B.1 7.1
5
25 mm (1.0 in)
22 mm (0.9 in)
ISO/IEC TR 14763-3 6.22
5
15 mm (0.6 in)
15 mm (0.6 in)
62.5 µm
TIA/EIA-568-B.1 7.1
5
20 mm (0.8 in)
17 mm (0.7 in)
ISO/IEC TR 14763-3 6.22
5
20 mm (0.8 in)
20 mm (0.8 in)
10
