# Phi before datasheet timing value

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?

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Can you post a link to the actual datasheet? – MikeJ-UK Apr 25 '12 at 10:38
– Toby Apr 25 '12 at 10:44
The context suggests "approximately" ($\approx$) but I've never seen a $\varphi$ symbol used for this purpose. – MikeJ-UK Apr 25 '12 at 11:03
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›‹€ – Tony Stewart Apr 25 '12 at 14:49
@Tony Stewart: here it is: Φ φ – Toby Apr 25 '12 at 16:02

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

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