Phil I don't do this much, but here is what I do for a low grade survey. I put this near the start of the low grade survey file. centreline grade BCRA3 # low accuracy # grade BCRA5 # high accuracy ... Endcentreline I am not sure if the same centreline can have multiple grades if you put grade statements in line with your data. The Therion Book description on page 19 would suggest not, as quoted below. “sd <quantity list> <value> <units> ▷ sets the standard deviation for the given measurements. The Quantity list can contain the following keywords: length, tape, bearing, compass, gradient, clino, counter, depth, x, y, z, position, easting, dx, northing, dy, altitude, dz. • grade <grade list> ▷ sets standard deviations according to the survey grade specification (see grade command). All previously specified standard deviations or grades are lost. If you want to change an SD, use the sd option after this command. If multiple grades are specified, only the last one applies. You can specify grades only for position or only for surveys. If you want to combine them, you must use them in one grade line. ” There are UISv1 grade options these days, but I will let someone else who knows them verify that they work… Bruce -----Original Message----- From: Therion [mailto:therion-bounces@speleo.sk] On Behalf Of Philippe Vernant via Therion Sent: Friday, 23 February 2018 10:11 AM To: List for Therion users <therion@speleo.sk> Cc: Philippe Vernant <phil.vernant@gmail.com> Subject: [Therion] grade commande Hi guys, Sorry to bother you with my dumbness, but I can't figure it out how to use the command grade based on the manual. Let say that I have a survey with poor measurements, how to I apply grade3 to this survey ? Thanks, Phil _______________________________________________ Therion mailing list <mailto:Therion@speleo.sk> Therion@speleo.sk <https://mailman.speleo.sk/listinfo/therion> https://mailman.speleo.sk/listinfo/therion