The goal of this project is to develop a new method of in-situ monitoring of the laser powder bed fusion (LPBF) additive manufacturing (AM) process. An instrumented build plate was designed, fabricated and installed in the NIST Additive Manufacturing Metrology Testbed (AMMT). An ultrasonic sensor attached to the bottom of the build plate detects acoustic emissions (AE) while the laser beam is scanning across the powder bed. Initial experiments with single powder layers showed a clear distinction in the RMS of the AE signal between environmental noise, the laser actively scanning and cracking events. Due to excessive cracking across the entire process map however, a build plate heater was incorporated along with a tilting mechanism for better powder spreading. Subsequent heated and unheated experiments showed no cracking at all, which is attributed to differences in powder composition. A thermal camera, coaxial with the laser beam, captured images of the laser melt pool in-situ. Another optical camera was used post-process to image powder denudation. Bolts with embedded strain sensors constrain the build plate and were intended to monitor the amount of residual stress as a 3D part is manufactured. Preliminary frequency-domain analysis of AE signals was carried out, leading to recommendations for future investigation.