<prompt> Field instrument used to measure bih weight:-Salters spring balanceElectronic weighing scaleMass produced balance scaleRoberval balance  <response>: - Field instrument to measure bih weight is Salters Spring balance kind of sling balance on which child is hung - Average bih weight 2.8kg - According to WHO, Low bih weight 2.5kg Very Low bih weight 1.5 Kg Extremely Low bih weight 1 Kg - Bih weight Doubles by 5 months Triples by 12 months Quadruples by 2yrs 