The performance of the calorimeter can be summarized as follows:

uniformity of the response of all counters within 1%;

linearity of the response to positrons within 1% over the energy range 1-30 GeV;

resolution
s (E) / E  =  (5.1 +/- 1.1) / E^1/2 + (1.5 +/- 0.5)
for a 3x3 array of counters and
s (E) / E  =  (5.1 +/- 1.1) / E^1/2 + (2.0 +\- 0.5) + (10.0 +/- 2.0) / E  for the whole calorimeter operating in the spectrometer, including the effect of pre-showering of the positrons in a preshower detector before the calorimeter;

position reconstruction with resolution about 0.7 cm;

stability in time of the response within 1%;

no observed degradation of performance due to radiation damage, within the accuracy of the measurements;

a hadron rejection factor exceeding 10 at the trigger level, and
a further off-line rejection factor of about 100;