Phi before datasheet timing value

Question

I have just come across this data sheet that specifies values from a timing diagram as

\$t_1\$ φ 300 ms, \$t_2\$ φ 50 ms, \$t_3\$ φ 25 ms, \$t_4\$ φ 15 ms, \$t_5\$ = 5 ms (minimum), \$t_6\$ φ 100 ms

The φ seems like maybe some kind of equivalence symbol. Any definite meaning?

page 6: http://www.vox-power.com/pdf/nevo600_user_manual_ra.pdf
The context suggests "approximately" (\$\approx\$) but I've never seen a \$\varphi\$ symbol used for this purpose.
THey probably didn't have that character in their font library. I use ~ when I don't have the ≈ and only use phi for angles e.g. LED beamwidth now where is my phi ¡™£¢∞§¶•ªº–≠«‘“πøˆ¨¥†®´∑åß∂ƒ©˙∆˚¬…æ÷≥≤µ˜∫√ç≈Ω¸˛Ç◊ı˜Â¯˘ÆÚÒÔÓ˝ÏÎÍŒ„´‰ˇÁ¨ˆØ∏”’±—‚·‌°‡ﬂﬁ›‹€

Toby · Accepted Answer · 2012-04-27 17:55:18Z

up vote 2 down vote accepted

OK so to sum up in an answer:

It most likely means "approximately" and was maybe used due to a lack of the correct symbol (≈) in the font set used for the document

edited Apr 27 '12 at 17:55

answered Apr 25 '12 at 23:54

Toby
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1 Answer