The following is a ticker response from the v2 api and for the ppc_btc pair.
{u'ticker': {u'sell': 0.00277, u'updated': 1413213963, u'buy': 0.00278, u'last': 0.00278, u'vol': 61.7349, u'vol_cur': 21718.61916, u'high': 0.00295, u'low': 0.00275, u'server_time': 1413213964, u'avg': 0.00285}}
Shows the btc volume being 61.7349 but I suspect that number is not since the last update
Here is another ticker from about a minute later
{u'ticker': {u'sell': 0.00276, u'updated': 1413214149, u'buy': 0.00278, u'last': 0.00278, u'vol': 61.68669, u'vol_cur': 21706.22291, u'high': 0.00295, u'low': 0.00275, u'server_time': 1413214149, u'avg': 0.00285}}
Are vol and vol_cur some accumulated number or are they the actual volume between ticker updates?