1.1 This test method covers the procedures used to conduct a temperature uniformity survey on a furnace used to heat treat steel products. This method is used to determine the capability of the furnace to meet the permissible temperature variation specified in the applicable product specification, or as agreed to by the purchaser and supplier of heat treat services. Survey documentation requirements, and the procedure used to subsequently establish the furnace working zone, are defined in this test method. 1.2 This test method covers heat treat furnaces in any of the following categories: 1.2.1 Continuous or semi-continuous conveyance furnaces, 1.2.2 Batch furnaces, and 1.2.3 Salt or liquid baths and fluidized beds. 1.3 This test method only applies when specified in the product specification or the purchase order. 1.4 Controlling a heat treatment of steel products using thermocouples attached to the extremities of each load is an alternative to performing a furnace survey. 1.5 By mutual agreement between the purchaser and the supplier of heat treat services, more stringent and/or additional requirements may be specified. The acceptance of any such additional