[AMOS] - Age in categories - latent or manifest?

Hi @all!

my name is Anni and I am new in this forum :wave:

I have collected data at a company and because of data protection I could just ask for the age in categories such as "under 20 years", "21-30 years", "31-40 years". In my model the age is a pretty important variable since it is supposed to determine three other latent variables.

My problem now is that I am unsure how to model the variable "age" :shakehead
On one side it could be seen as a latent variable with an disturbance term measured by one manifest variable, since the kategories lead to some kind of error or inaccuracy. On the other side I age yould be modeled as manifest variable with or without a disturbance term. My point is that I am not sure wheather measing in categories produces an error which is modeled in the SEM or not?

Moreover, if "Age" is modeled as a manifest variable it belongs to the measurement model but since my hypotheses include "age" doesn't it also belong to the structural model?

I you can understand what i mean and can help me. Looking forward to hear from you!
Thank you in advance!

Best wishes