When using pH test paper/indicator sticks you should also: 1  Make sure to only use paper/sticks that have not been previously wetted. 2  Wait for the color to stop changing (1-2 minutes maximum) before matching the paper/stick to the color key.
Red and White Regulatory Signs. Red and white regulatory signs tell you about regulations you must follow. For example, the DO NOT ENTER sign tells you there is danger ahead because vehicles will be coming toward you, usually on a freeway off-ramp or one-way street. The WRONG WAY sign may accompany the DO NOT ENTER sign.
The ordinance would then allow on-premise signs and prohibit off-premise signs. This type of ordinance does not prohibit off-premise signs that display noncommercial messages. This kind of sign regulation came before the Supreme Court in Metromedia and caused problems under the free speech clause. The plurality opinion upheld a ban on off-premise signs although the ordinance allowed on-premise signs, but struck down the section that prohibited noncommercial messages on on-premise signs.