diff --git a/spectrometer.py b/spectrometer.py
index d3b9b7c..6bdc3a0 100644
--- a/spectrometer.py
+++ b/spectrometer.py
@@ -3,7 +3,6 @@
 import argparse
 import json
 import sys
-import time
 
 from hpcs6500 import HPCS6500, find_hpcs_port
 
@@ -17,11 +16,8 @@ def measure():
     dev = HPCS6500(port)
     try:
         dev.identify()
-        dev.psu_on()
-        time.sleep(0.5)
         reading = dev.take_reading(psu=False)
     finally:
-        dev.psu_off()
         dev.close()
 
     if reading is None: